geometry-and-trigonometry

[upper karma]

If u can do algebra u can do geometry

[dark sparrow]

do not give up, @pale crow

you know what "halfway" means, right?

[brisk yoke]

dx beth

do u know the midpoint formula

[upper karma]

i used to know it but

i frogit it

[dark sparrow]

okay look

there's no point in presenting the "midpoint formula" as a black box

[brisk yoke]

huh

[pale crow]

what

[vale raven]

(Translation: Don't blindly follow formulas without understanding them)

[brisk yoke]

welp how do u do it without a formula then

(Translation: you can't)

[dark sparrow]

sigh

[brisk yoke]

im getting good at this

[dull egret]

(note: you can be sure they would understand if you just showed them the formula)

:P

[brisk yoke]

^

they can just apply it

[vale raven]

Yea, but that wouldn't be very helpful at all

[dark sparrow]

NO!

[vale raven]

Don't blindly follow formulas without understanding them c:

[dark sparrow]

applying a formula without understanding it is VERY unhelpful

okay @pale crow
do you know how to calculate the average of two numbers?

[pale crow]

Yes....

U add then dvide

[dull egret]

they will understand once you show them. it makes total sense

[pale crow]

Add them and divide by 2

[dark sparrow]

so that means you also know how to compute the number halfway between two numbers

(a+b)/2 is the number halfway between a and b

[dull egret]

i can see the point in your long winded ealborations for complicated things, but this is dead simple. like srsly.

[pale crow]

I know

[vale raven]

Shh

Let √2 do her work

[dark sparrow]

so now

[brisk yoke]

someone said ann was a guy

falso?

[dark sparrow]

i am not a guy

[brisk yoke]

told ya

[dark sparrow]

@pale crow are you still here?

[pale crow]

Yes

[dark sparrow]

let's find the midpoint of (-3, -7) and (-1,1), since that's one of the problems you posted

[pale crow]

Ok!

[dark sparrow]

so first let's find its x coordinate

what number is halfway between -3 and -1?

[pale crow]

2.5

Negatove

[dark sparrow]

-2.5

[pale crow]

Tes

Yes*

[dark sparrow]

are you sure though?

😛

(-3 + (-1))/2 = ?

@pale crow

[upper karma]

hi uh

where's the liberal arts discord in ehre

like adding/subtracting polynomials and stuff like that

[pale crow]

I kinda give up, im at lunch and ill just come back to this later

Thanks

[dark sparrow]

@upper karma how is that liberal arts?

[upper karma]

IDK YOU TELL ME

MY MATH CLASS IS called liberal arts

and i learn about THAT

wait

yeaa

[dark sparrow]

also, i'm very surprised point addition and multiplication of a point by a number are not taught as operations at this level

lol

like, it'd simplify some things tremendously

like the midpoint formula would just become mid(A,B) = (A+B)/2, almost identical to the average of two numbers

(x, y) + (z, w) = (x+z, y+w) and k * (x,y) = (kx, ky)
that is literally all it takes lol

and obviously dividing by a number is multiplying by its reciprocal

lol

[upper karma]

(3x-5) (5x+1)

the answer would be

2x-6 right

[dark sparrow]

what?

are those meant to be multiplied?

[upper karma]

yes

WAIT.

no

[dark sparrow]

then no, not even close

[upper karma]

subtracted

subtracted sorry

[dark sparrow]

(5x+1) - (3x-5)?

yes, that will be 2x - 6

[upper karma]

yea

okay thank you sm

[dark sparrow]

wait

no

2x + 6

i can't read

it's 2x + 6

[upper karma]

okay thanku

[jade igloo]

Is this trigonometry stuff

Cause i need help with that

[dark sparrow]

yeah sure trig goes here

ask away

[jade igloo]

Like the soh cah toa

I knw where to put the A O and H

[dark sparrow]

...that's a mnemonic i don't consider good

[jade igloo]

Bit isnt there smaller letters

Like soh is like

Wait

S is sine o is oppisite h is hypotanuse

[dark sparrow]

"soh" is short for "sin(t) = opposite/hypotenuse"

[jade igloo]

For sine u do o×h-1 or o/h

Yeah

[dark sparrow]

h**^**-1, if you insist

[jade igloo]

In physics we don't use the /

So im learning without

See the triangles

Top pic

Wait

[dark sparrow]

i find "m s^-1" the most idiotic notation possible for meters per second

anyway, this is how i tend to think of sin, cos and tan

[jade igloo]

Ya

Wait

[dark sparrow]

ofc r can be replaced with any other letter or quantity

[jade igloo]

Whats the one when you label the opposite to the capital letters the smaller letters

[dark sparrow]

uh

[jade igloo]

Like you have a triangle labeled with the A H and O

Then theres smaller ones oppisite on the lines as the capitals are on the corners

Oh wait

Thays for area right?

That's *

[dark sparrow]

...you might be referring to the conventional choice of notation for the law of sines

like, with angles A, B and C and sides a, b and c opposite to them

[jade igloo]

Yes

I forgot what thats used for x.x

[dark sparrow]

then a/sin(A) = b/sin(B) = c/sin(C) = diameter of the triangle's circumcircle

[jade igloo]

X.x how do you kniw this much

And ya the sine rule or something

[dark sparrow]

law of sines

that's how it's usually called in english, iirc

[jade igloo]

Ya here its the sine rule

Then we have the cosine rule?

[dark sparrow]

yeah, that relates three sides and an angle

[jade igloo]

How do i knw which is which

[dark sparrow]

...i'm not sure how to answer that

the law of sines lets you go between a side and an angle opposite to it
the law of cosines lets you find the third side of a triangle given the two other sides and the angle between them, or an angle given all three sides

both may be applicable in a given situation

...i really should go to sleep

it's 01:16 here

[jade igloo]

Damn

Gn

Teach me your brains x.x

[dark sparrow]

...that's going to be very hard if not impossible

[jade igloo]

How do you know a lot ;(

I couldnt even answer my full maths papers

Questions were too long and had low time

[dark sparrow]

tons of practice

[last siren]

tons of intelligence as well

[umbral rivet]

@dark sparrow is very knowledgable :3

[upper karma]

^

[topaz valley]

throws breadsticks at @foggy oxide

[foggy oxide]

what @topaz valley

[topaz valley]

I thought you said something

[foggy oxide]

i did

[umbral rivet]

eats breadsticks

<~<

~>

omnomnom

[foggy oxide]

For those who like to find unknown theorems i have a recommendation about haruki theorem

[umbral rivet]

Read haruki as "haruhi"

And started getting flashbacks 👀

[foggy oxide]

xDDDD

[foggy oxide]

i was playing with a problem

look at that beautiful symmetry

[west dune]

Hey

Guys

[dark sparrow]

hi

[west dune]

https://cdn.discordapp.com/attachments/172645867570987008/355786908141617154/JPEG_20170908_214937.jpg I have that triangle

The middle 1

[dark sparrow]

the one with the yellow things?

[west dune]

yes yes

[dark sparrow]

alright

[west dune]

These are my calculations

[dark sparrow]

what are you asked to find?

and what do you know?

[west dune]

What I know is inside the picture above

I need to find that ABD = CBE

I made ABD as my variable

[dark sparrow]

erh

[west dune]

and I've calculated untill I got to DBE which is 90-2 alpha

[dark sparrow]

i'm having trouble deciphering what exactly you tried to show in the picture

[west dune]

Hmm Im saying all of these right now.

[dark sparrow]

are AD and BD meant to be equal?

[west dune]

Yes.

[dark sparrow]

...anything else?

[west dune]

I need to do 90 - 2alpha - 90 - alpha

to calculate EBC

[dark sparrow]

is anything else given other than AD = BD?

[west dune]

and its = -3alpha.

oh ye 1 sec

BE right to AC

ABC = 90

And the triangle ABC is a right triangle.

[dark sparrow]

is it given that DE = EC?

[west dune]

No.

[dark sparrow]

right

[west dune]

To make it happen I need to get the answer to the question 😅

I'm on that for 15min now.

[leaden kindle]

They are gonna help you find an answer, not directly give it ¯_(ツ)_/¯

[west dune]

ofc ofc

I got 90% just that bit kills me.

[dark sparrow]

and you're trying to prove that angles ABD and CBE are equal?

[west dune]

Yes.

[dark sparrow]

hmm

okay one moment

[west dune]

👍

[dark sparrow]

are you allowed to use trigonometry?

[west dune]

nope

[dark sparrow]

crap

that makes it much harder

[west dune]

ADB = 180-2alpha
BDE =  180 - 180 -2alpha = 2alpha 
DBE = 180 - DEB - 2alpha => 180 - 90 -2alpha = 90 - 2alpha```

[dark sparrow]

actually nevermind

you can do it without trig

you're allowed to use similar triangles, right?

[west dune]

ofc

[dark sparrow]

yeah okay

consider the triangles ABC and AEB

triangle ABC has angles α, 90, and 90-α

in that order

triangle AEB also has angles α, 90, and 90-α

so they're similar

[west dune]

Hmm let me see 1 sec

[dark sparrow]

actually

nevermind

[west dune]

yep

lol

[dark sparrow]

you don't even need that here lol

angle C = 90-α

as is hopefully obvious

so angle EBC is forced to be equal to α

[west dune]

I cannot just say that. I need to prove what's EBC

yes it does.

[dark sparrow]

yes you can. triangle ECB has angles 90, 90-α, and EBC

EBC must be α

[west dune]

How do you know there's an alpha there?

You got to prove it first.

[dark sparrow]

you are allowed to use the fact that the angles in any triangle sum to 180 degrees, right?

[west dune]

Yes

[dark sparrow]

90 + (90-α) + EBC = 180

180 - α + EBC = 180

do i need to continue?

[west dune]

I dont get how do you think there's α inside triangle EBC

[dark sparrow]

do you understand why angle C = 90-α?

[west dune]

Yes because
180 - alpha - 90

[dark sparrow]

yes

so

[west dune]

Ah wait.

[west dune]

OMG

so.

hm

it's alpha

the pic you've sent

[dark sparrow]

yes

[west dune]

b = alpha.

but.

180 - 90 - 90 = 0

-alpha = -alpha

🤔

[dark sparrow]

...what's the problem?

[west dune]

It cannot be **-**alpha

180 - 90 - 90 - α = -α

[dark sparrow]

180 - 90 - (90-α) = 180 - 90 - 90 + α

[west dune]

oh

wow

amit

you are an idiot

- * - = +

[dark sparrow]

...pardon?

[west dune]

My name is Amit

[dark sparrow]

oh

[west dune]

thank you so much

I forgot it should go in parenthese.

Thank you!

[upper karma]

xD

[upper karma]

yo

[dark sparrow]

👋

[rose rover]

Hello

There's this question: POQ is a line. Ray OR is perpendicular to line PQ. OS is another ray lying between rays OP and OR. Prove that angle ROS = 1/2 (angle QOS - angle POS)

Any takers on how to solve it?

I think I've almost got it

But not sure

[vale raven]

Draw another ray OT on the other side such that angle POS = angle QOT

[vale raven]

Then it should be fairly straightforward

[rose rover]

Ah

[dark sparrow]

angle POS = 90° + α

angle QOS = 90° - α

...switch around P and Q on my pic

there

[rose rover]

Ah

If I draw, OT angled the same as OS, then I could say POS + ROS + ROT = QOR + ROS

And since ROS = ROT

and QOR + ROS = QOS

We could say, POS + ROS + ROS = QOS

Nvm I got it

Thx

It'll just be like, POS + 2ROS = QOS

2ROS = QOS - POS

ROS = (QOS - POS)/2

[daring oxide]

help

[whole onyx]

Try (0,12)? I posted this in the questions chanel, then went afk for a bit.

You could write it as 1/16(x+0)^2+8

Vertex then is 0, 8

And if you add 1/4a, or 1/(.25) to 8, you get a focus of (0, 12)

Imma tag you for no reason now. @rockhardlee

@daring oxide

Ah. There it is. Now I'm going stop for the while.

[foggy oxide]

Hm this problem remember me something

Calculus helped me with a vestibular problem once

i used it to found the vertex of the parabola

[west dune]

Parallels are creating 90°

?

[dark sparrow]

no

[west dune]

:/

I'm stuck at something

[dark sparrow]

two lines are parallel if they don't intersect

two lines are perpendicular if they make an angle of 90°

[west dune]

Sorry for the hebrew btw.

The middle triangle

And sorry for broken neck too :/

I need to prove that BE = CE

so I thought about proving that DCB is a Isosceles triangle so then I can say that
DB is central to CB

And I cannot find how :/

DE || AB
AD = DB = DC```

Any Ideas √2?

[dark sparrow]

i'm out of energy

[west dune]

Ah

Someone knows if the 2 lines that I dont know how to say it in english but
when DE || AB in that triangle does it make 90°?

[heavy path]

amd i dumb or wtf? Two vectors are given by:
a=4.1i^−4.0j^+4.0k^
and
b=−2.0i^+1.9j^−5.7k^
.
Find the magnitude of a+ba+b. (All units are in meters)

i got this 2.1-2.1-1.7

but like

[west dune]

Is this releated to geometry even?

[heavy path]

its vectors

so i would assume

[west dune]

I thought my question is ez :/ why no one answers

[heavy path]

DE parallel to AB?

[west dune]

Yes.

[heavy path]

what is the question just prove why BE is equl to CE

[west dune]

Yes

[heavy path]

http://www.deployday.com/triangle-congruence-proofs-worksheet/

i can only hope you find something here

i was trying to remember but i suck at trig

i rather do extensive math than shapes

[west dune]

k thx

[heavy path]

i feel like i got it i just cant explain it, sorry m8.. :[

[whole onyx]

Uhh... Perhaps say that DC=DB, therefore triangle CBD is an isosceles. Then perhaps ED is parallel to AB, so EB is perpendicular to ED and that ED bisects BC.

oh... this was 4 hours ago...

he/she prolly figured it out

[whole onyx]

and uh for the vectors, there's a probability that this is wrong, but here's what I got after a short refresher on gewgle. 21.8859... with a ending vector of 17.3 i^+13.27j^-1.91k^

[grave lance]

@whole onyx I like that, gewgle

[inner patrol]

hey

could anyone help me with my math homework

I have a test tomorrow

There's this one problem that's bugging me

[upper karma]

What is it

[inner patrol]

the surface of the ball and that of the right circular cone illustrated here are covered with fresh paint. The ball is put on a table and rolls in a given direction. After that: what is the figure that corresponds to the mark left on the table? 2. How far has the ball gone?

the diameter of the ball is 12,5 cm

[upper karma]

Uhhh

Shiz

Idk

@inner patrol Sorry

[inner patrol]

aaaa

[upper karma]

Mhm

Ask help

[topaz valley]

sqrt(a^2+b^2) is the distance between the origin and a point (a,b)

Is there a geometric meaning to something like cbrt(a^3+b^3) ?

[inner patrol]

mmh

[vapid kettle]

yeah that's the 3-metric

p-metrics for p-prime come up in analysis

https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm

[inner patrol]

@vapid kettle what is the formula to calculate it

simplify it please

I'm only in 9th grade

[foggy oxide]

well

@inner patrol

are u here

?

[inner patrol]

yes

[foggy oxide]

what was the question

that u asked

[inner patrol]

the surface of the ball illustrated here is covered with fresh paint. The ball is put on a table and rolls in a given direction. After that: what is the figure that corresponds to the mark left on the table? 2. How far has the ball gone?

the diameter of the ball is 12,5 cm

[foggy oxide]

Hmm

Is this discursive ?

i think there is no enough information

[inner patrol]

it rolled 4,3 turns

[foggy oxide]

any more information ?

[inner patrol]

nope

but I forgot to say it rolled 4,3 turns

[foggy oxide]

Alright

I'll give you some hints

Imagine that this is a circuference

[inner patrol]

okay

[foggy oxide]

Something like

this

[inner patrol]

oh ok

[foggy oxide]

do you know

how to calculate

the lenght of a circuference ?

[inner patrol]

pi x radius2

[foggy oxide]

yes

[inner patrol]

but what shape will the mark be

[foggy oxide]

if the clrcuference rolled exactly only one time, what do you think would be the lenght of the painting ?

sorry but i have no idea about that part ...

a line idk

[inner patrol]

If the circumference is rolled exactly one time

it would be uhh

[foggy oxide]

try to imagine the paint

[inner patrol]

12,5 cm?

[foggy oxide]

wait wait

that is the diameter

[inner patrol]

yes

information : 12,5 cm diameter and it rolled 4,3 turns

[foggy oxide]

hm, i know

[inner patrol]

do you know how to do the math problem

[foggy oxide]

i think i do

but i'm not preety sure

[topaz valley]

Go for it, i'll check it

[inner patrol]

@topaz valley I'm sorry for leaving out a bit of information. The ball rolled 4.3 times

[topaz valley]

And you're trying to see how far it rolled?

[inner patrol]

yup

its got a diameter of 12,5 cm

and its covered with paint

so it leaves a mark

[foggy oxide]

one question

[inner patrol]

they wanna know the distance

[foggy oxide]

Did u learn in school how to calculate the lenght of a circuference

that might help me about something

[inner patrol]

pi x radius2

[foggy oxide]

yes

but

did u learn it at school

?

[inner patrol]

Yeah

[foggy oxide]

or you saw it on internet ?

hmm

[inner patrol]

we started calculus and algebra

[foggy oxide]

idk

so...

[inner patrol]

so it would be 12,5 cm (diameter) x 4,3 turns

[foggy oxide]

or

12,5*pi*2 * 4,3

[inner patrol]

yeah that seems about right

[foggy oxide]

xD

[topaz valley]

the equation for circumference is C=pi * d

=tex C=\pi d

[inner patrol]

the editors of the book wouldn't make it so easy that its only 12,5 x 4,3

[foggy oxide]

yeah

or

pi2r

it's the same

xD

ow

Blue

[topaz valley]

Isn't 12,5 the diameter?

[foggy oxide]

sorry

yes

!

[inner patrol]

it is

[foggy oxide]

so it's, pi *12,5

i think it's correct well

[inner patrol]

or find the radius via the diameter

[foggy oxide]

not necessary

[inner patrol]

by doing diameter divided by two

thats what my teacher told me

[foggy oxide]

yes, you can do that, but it's not really necessary

[inner patrol]

my teacher is bad at explaining imo

[foggy oxide]

only if you gonna work with radius

that's very sad to hear

don't hate math because of your teacher pls

[inner patrol]

I don't

[foggy oxide]

it's the most interessant area of knowledge

[inner patrol]

I got 53% in math last year

I needed 60% to pass

7%

[foggy oxide]

and it's probably one of the only things you can trust in your life

[inner patrol]

alright so lets recap

what do I need to do

[foggy oxide]

i think if you turn 360 degrees it would paint the lenght of the circuference in a formact of a line

assuming the ball is going straight

[inner patrol]

''in a given direction''

[foggy oxide]

Yeah

[inner patrol]

so I need to do pi * 12,5

[foggy oxide]

yes that's the lenght of the circuference

now you just need to think how many times the circuference will be printed in the table xD

(something that is given)

[inner patrol]

alright so the circumference is 39,2699 cm squared

[foggy oxide]

yeah

[topaz valley]

Not cm^2

[foggy oxide]

it's a lenght

[inner patrol]

oh

[topaz valley]

Just cm, because circumference is the length around the ball

[foggy oxide]

i didn't saw the cm^2

[inner patrol]

oh okay

okay so I do 39,2699 times 4,3 turns?

oh no wait

[foggy oxide]

yeah xD

[inner patrol]

divided

[foggy oxide]

nah ...

[inner patrol]

do I multiply or divide

[foggy oxide]

thin a lil bit

about it

what makes more sense ?

[topaz valley]

39,2699cm for 4,3 turns

[inner patrol]

yeah dividing would be to only know 0.1 turn

[topaz valley]

So if it turns once, then its gone 39,2699 cm

if it turns twice, then its 2*39,2699 cm, right?

[inner patrol]

yeah but its 4,3

[inner patrol]

so 4,3 x 39,2699

[foggy oxide]

that's your sphere seeing from a 2d perspective

yeah xD

[inner patrol]

and then its over

?

[foggy oxide]

did u answered the first question

what is the geometric figured formed ?

[inner patrol]

I said rectangle lol

[foggy oxide]

well, are you sure about it ?

[inner patrol]

nope

I mean a figure would be a square / rectangle / cone / sphere etc

not just a line

[foggy oxide]

Well, that's more subjective than exact in this problem

but if i was the teacher

i would consider both line and rectangle

I can assure you that it's correct to call, a line as a geometric figure

[inner patrol]

oh ok

[foggy oxide]

any kind of doubts about geometry you can tag me here right ?

i'll answer you tomorrow

i'm going to sleep rn

[inner patrol]

Oh alright thanks!

[foggy oxide]

gtg, school in 6 hours xD

[inner patrol]

So I multiply the circomference by the

turns

and its done

[topaz valley]

yes

[foggy oxide]

yeah : D

[inner patrol]

Well thanks guys! 😄

I gtg to school in 8 hours

I have a math exam tomorrow

[foggy oxide]

So we both are in trouble with sleeping hahaha

[inner patrol]

yup

my teacher is randomly selecting 1 math problem he assigned us

and thats our exam

[foggy oxide]

my childhood habits are persistent

if it's not given a figure, try to draw it propely or do your best to imagine it at your head

[inner patrol]

thanks for the help and the tips

Hopefully I will pass my math test tomorrow!

[lusty sparrow]

How do you find the perimeter of a triangle that isn't equilateral?

[thorn talon]

What info is given?

[foggy oxide]

Axonum, there area alot of ways to find it

even if you have one side and 2 angles, you can find the perimeter

if you have one side and the inradius + a angle, i think you can also find it

[lusty sparrow]

How do you find the equation of the line perpendicular to another line when either x or y is unidentified?

[dark sparrow]

when either x or y is unidentified
huh?

[dark sparrow]

#3?

[lusty sparrow]

3 and 5

[dark sparrow]

okay so for #3

x - 5 = 0

or in other words x = 5

this describes a vertical line

is that clear?

[lusty sparrow]

Yes

[dark sparrow]

what lines are perpendicular to vertical lines?

[lusty sparrow]

So y is 0?

[dark sparrow]

what?

[lusty sparrow]

Horizontal lines

[dark sparrow]

yes

so

what horizontal line passes through your point?

(btw, your answer for #4 is wrong, but we'll deal with #3 first)

[lusty sparrow]

Not sure

Okay

[dark sparrow]

what is the y coordinate of your point?

[lusty sparrow]

-5

[dark sparrow]

so

[lusty sparrow]

But the equation isn't in y equals mx plus b

[dark sparrow]

y = -5

y = 0x - 5, if you're pedantic

so yes it is in that form

[lusty sparrow]

Oh

So there is no x

And that results in 0

[dark sparrow]

i'm not sure what you're trying to say there

[lusty sparrow]

I'm confused myself

So how do I start for question 3?

Do I put my point on (5,0)?

[dark sparrow]

what?

what point?

you do realize horizontal and vertical lines are a bit of a special case when it comes to perpendicularity, right?

equation-wise, that is

@lusty sparrow?

[lusty sparrow]

I asked my teacher for help and I understand it now

But I'm not sure about #4 how I got it wrong

[dark sparrow]

do you know the template for a line's equation in point-slope form?

[lusty sparrow]

Yes its

Y - y1 = m(x - X1)

[dark sparrow]

yes

so with the slope, which you correctly calculated as -3/2, and your point, (x1, y1) = (-4, -7), what does that become?

[umbral rivet]

👀

[lusty sparrow]

Y - 7 = -3/2 (x - 4)

[dark sparrow]

no

that'd be the case if your point was (4,7)

not (-4,-7)

[lusty sparrow]

Oh is it two negative is a positive rule?

So if it's negative points it becomes +

[dark sparrow]

two negative is a positive rule?
rule

[lusty sparrow]

Y + 7 = -3/2 (x+4)

[dark sparrow]

yes

[lusty sparrow]

Thank you

[spiral lintel]

Can I still some help with question 24 and 25?

[dark sparrow]

oh god 2-col proofs

🙅

[west dune]

Hey guys

I got a problem with question 19

Which I cannot manage to solve

[foggy oxide]

Hello

wELL

[west dune]

AD cuts angle BAC
0.5 * AB = AC```

I need to prove that

2 * DC = AB

I've set set DC as my X

And I'm stuck

[foggy oxide]

hmm

well, i think i know how to prove it

[west dune]

Can you please try to explain?

[foggy oxide]

any more information ?

[west dune]

Nope

[foggy oxide]

You know that the cotangent it's equal to 0.5

let me draw it

[west dune]

No trigo is allowed

Since we did not learn it yet

[foggy oxide]

alright

but can you use the concept of ratio and similiarity ?

[west dune]

Similarity , yes

[foggy oxide]

aight

can you write

everything

in terms of only one variable ?

[west dune]

Ah , I dont think I understand what do you mean

[foggy oxide]

🤔 like using pytaghorean theorem a nd the information AB = 2AC

[west dune]

ahhh

I know that DB = 2 * AC

[foggy oxide]

try something like that

i think pytaghorean theorem might work

[west dune]

I need to translate it . 1 sec

English isn't my native lang

[foggy oxide]

np

[west dune]

ohhh I know that

ofc lol

=tex a{2} + b{2} = c{2}

[west dune]

fail

I dont know how to use this bot

at all

[foggy oxide]

c^{x}

[west dune]

ah ok

[foggy oxide]

= tex a^{2}

[dark sparrow]

=tex a^2 + b^2 = c^2

[foggy oxide]

first of all

let x+z = b

k it's what "u want"

[west dune]

let x + z = b ? Are you Javascript Bro?

😅

[foggy oxide]

xD

well, what do you know ?

[west dune]

hm

[foggy oxide]

show all informations

[west dune]

Should I give AB the variable of y?

And DC the variable of X

[foggy oxide]

i just rotated the triangle

you can give it any name you want

[west dune]

I will write a prove chart rn

[foggy oxide]

alright

idk what is chart

but ok

[west dune]

¯_(ツ)_/¯

So , AB = 2y

ah wait

AC = 2y and AB = y
So I will not have to calc decimals

[foggy oxide]

well try to use pythagorean theorem then in order to see something

[west dune]

Yep that's my equation now.

wowwww

sqrt of 3y

omg

[foggy oxide]

Isn't BC the side

[west dune]

Yes ... you're right

[foggy oxide]

AB = hypotenuse
BC , AC are legs

[west dune]

=tex BC = y^2 + BC^2 = 2y^2

Thats the one.

[west dune]

sqrt of y^2?

[foggy oxide]

you're kinda of making confusion xD,

[west dune]

ah ye

sorry for that

that's what I mean

I got it

[foggy oxide]

here

and

?

[west dune]

I need to think how to

[foggy oxide]

AD*

[west dune]

😅

I have the whole big trinangle now

AB = 2Y
BC = 2Y
AC = Y```

I can I get the others now

I did not use AD cuts angle BAC

How can it help me?

https://cdn.discordapp.com/attachments/326138757474680852/356862715907801098/JPEG_20170911_210438.jpg

I got the big triangle right?

[foggy oxide]

...

i'm actually stupid

i'm sorry

BC = 2AC

[mossy oriole]

hi

Ive been really confused with this

the question is: how many planes are shown in this figure>

[robust socket]

I'd say 6 but it's just a wild guess

[mossy oriole]

I can count 5

but IDK

🤷

[spiral lintel]

This number 24 doesn't make sense to me

[whole onyx]

uhh draw it out. Here's what I got

pardon the bad drawing

using mouse

also, RST and NSW aren't necessarily what they look like angle-wise

Quickly, and perhaps mistakenly, I'd find 1/4 measure of RST to find the angle of RSZ (cuz it's the angle created by the bisector of a bisector, or half of a half of an angle).

and for NSZ, I'd find the measure of RSZ and double it, cuz NSZ is bisected by SR.

wow-ee am i always late, huh. 45 mins

I'll tag you anyways @DOE#5070

@spiral lintel

[spiral lintel]

thanks for the effort

and time

[upper karma]

Does no one know how to use the line tool 🤔 @whole onyx

[boreal flame]

I need help

Show, without using the edge angle that, Thales Sats: Each triangle is written in a circle on one side, the circle's diameter is right-angled

Pm me thank

[rare talon]

What do you mean by edge angle?

Here

[boreal flame]

Wait

Let me show ya

[rare talon]

I will assume it's the angle on the big triangle.

Denote the big triangle is ABC, where AB is the diameter.
We want to prove that <C = 90 degrees ok?

[boreal flame]

Yes!

Exalty

[rare talon]

Now denote the center of triangle as O

See triangle AOB, you can just make <AOB = x degrees okay?

I mean

[boreal flame]

Draw it is more easy for me

[rare talon]

AOC

Sorry

[boreal flame]

Right ?

[rare talon]

Yeah

But you don't know C is 90 degrees yet

You want to prove it

See triangle AOC

You can let the <AOC = x degrees

[boreal flame]

Yes

What is O?

[rare talon]

O is the center of the triangle

Sorry

Circle

[boreal flame]

Diameter

?

[brave drift]

O is the center of the circle

[boreal flame]

I'm right?

[brave drift]

Exactly

[boreal flame]

Ok now?

[rare talon]

Now let <AOC = x degrees

You should notice that triangle AOC is isoceles (because OA = OC = the radius of the circle)

Okay?

[rare talon]

Then <CAB = <ACO right?

Do you follow this so far?

[boreal flame]

Wait

Let me check

Are they same?

U sure?

[rare talon]

Yeah

[brave drift]

When triangles are isosceles, opposite angles are always equal

[rare talon]

ACO is an isoceles triangle, since CO = AO = radius of the circle

[boreal flame]

I know that is why I make

/

Ok right

They are same but not same degrees

[rare talon]

Degree of <CAO and <ACO are the same too

[boreal flame]

I know

[rare talon]

So do you agree with me? xd

[boreal flame]

Yr

Go

[rare talon]

You already know that <AOC = x

Then <ACO + <CAO + <AOC = 180 degrees

Since <CAO = <ACO and <AOC = x
Then:
<ACO + <ACO + x = 180 degrees
2 <ACO = 180 - x
<ACO = 90 - 1/2 x

Get it?

[boreal flame]

Only fuck

U are smart

What i did last night was this

[rare talon]

It's not finished

Anyway

[boreal flame]

Wait Ok Nya keep go

[rare talon]

Now you know <AOC = x degrees, then <COB = 180 - x right?

[boreal flame]

X degrees mean 90- 1/2x?

[rare talon]

What?

[rare talon]

<ACO is 90 - 1/2 x, not x is 90 - 1/2x

[boreal flame]

Ok

So I'm follow u right

[rare talon]

I guess I'll leave that to someone who is better at explaining

I don't like to be followed blindly

[boreal flame]

But keep going

COB=180 -X

Bro don't leave me :(

[rare talon]

Do it yourself

You should figure out

What do you find on triangle COB ?

[boreal flame]

They also same

[rare talon]

COB is an isoceles triangle

I think you mean that

[boreal flame]

See i know

:D

[rare talon]

Then?

[boreal flame]

Hmm

Cam I try on my own for 5 min then I show u?

[rare talon]

Okay

Make sure write it so I can understand

[boreal flame]

Now look

I'm right ?

The algebra

Right?

@rare talon @rare talon

[rare talon]

Wait

That's much simpler

But

[boreal flame]

I want simple

[rare talon]

You didn't prove anything

[boreal flame]

Hmm

[rare talon]

I believe you didn't prove anything in your proof

[boreal flame]

Oh

[rare talon]

You shouldn't assume <C = 90 degrees !

[boreal flame]

Teacher told me yesterday this is done

Yes

How can I do that?

I'm not at that level

My math is still basic

Can u show me pls

[rare talon]

You know that v + w = <C right?

[boreal flame]

Yes

....

[rare talon]

Yeah

[boreal flame]

Now we got problem

[rare talon]

Try to find v + w

[boreal flame]

I'm so bad 😭

[rare talon]

Don't assume it's 90, but show me why it's 90

Degres

*degrees

[boreal flame]

Cause

[rare talon]

asdf

[boreal flame]

This is triangle

[rare talon]

Then?

[boreal flame]

A^2+b^2=c^2

[rare talon]

Wrong track

[boreal flame]

I'm lost right now

[rare talon]

You can't assume ABC is a right triangle, from the start

[boreal flame]

Couldn't tell me ? From COB

[rare talon]

https://cdn.discordapp.com/attachments/326138757474680852/357166082714501133/20170912_161018.jpg I'll just use this, okay?

Do you have an idea why <CAO = <OAC ?

[boreal flame]

Cause

I show u on pics

Before

/ //

[rare talon]

Don't use only picture

Use reasoning why it is the same

[boreal flame]

I d9nt know word in English

[rare talon]

What's your language?

[boreal flame]

Swedish

[rare talon]

I'll try to translate , I guess

[boreal flame]

För det första o triangeln finns två lilbent trianglar

Aco= 180 grader

Boc= 180 grader

[rare talon]

lilbent = isoceles?

[boreal flame]

Sen

Yes

[rare talon]

Okay

<ACO =/ 180 degrees

Anyway, just take this to PM

[boreal flame]

?

[rare talon]

I don't want to see you using swedish here 😂

[boreal flame]

:(

Pk

[lilac island]

Hello

[umbral rivet]

Hoiiii

[modest locust]

Hey

[rough juniper]

Trying to get the perimeter of the triangle, would like an example/a starting point please!

[river garnet]

the perimeter means you add up all the sides

unless if you're given a specific number that is the perimeter and if you're asked to solve for x

then as much as i can see from the question above i believe it wants you to calculate the area of the triangle in terms of x

but i haven't seen the entire question

[rare talon]

You can solve for x , I think?

[river garnet]

i'm not very good at euclidean geometry

i don't know all of the rules

[rare talon]

I just want to confirm

[river garnet]

so it is possible

[rare talon]

Is triangle on number 2, a right triangle?

[river garnet]

yes

there is a square box on the left bottom corner

that indicates perpendicularity

usually

[rough juniper]

My idea was to use pythagorean therom and simplifie it

[river garnet]

what is the question asking of you to solve for?

x, the area or the perimeter itself?

pythagorean could help

[rare talon]

If you can find x

You can easily find the area / perimeter

[river garnet]

@rare talon the question could just be to write the area perimeter as a "function" of x

but it is unlikely

[rare talon]

It is possible

But x is definitely fixed

To 1 or 2 value

[river garnet]

what made you conclude that?

[rare talon]

Or actually no x satisfy

See problem 2:
13^2 + (2x+20)^2 = (3x-11)^2

With pythagoras

It's a quadratic eq

[rough juniper]

@rare talon yeah

(sorry, server made me wait for 10 minutes even though I already did beforehand)

[river garnet]

if the last side that is 13 was also an equation

you might have had a problem

but it wasn't

so kudos

[rough juniper]

^

[crude kraken]

Does a curve count as one side, infinite sides, or is there some way to count them?

[river garnet]

is that a philosophical question or a mathematical?

[crude kraken]

I-... good question.

I had to do a captcha where I typed how many sides a slice of pizza had, and one of the sides is curved (Because a slice isn't a perfect triangle) so I have to think of this

[river garnet]

mathematically you could think of a circle being the "infinitely many even sided shape"

as in the limit the sides increase and as they increase the picture looks smoother

and approaches a circle

@crude kraken that's i believe related to the idea that Kepler had when he was trying to prove the area of the circle

he took these "almost" wedges

which were really triangles

inside a circle

and he opened it up

to get a triangle

[crude kraken]

Mhm

[river garnet]

and then due to the height being r and the long edge being 2pir since the circ was 2pir he ended up with pi*r^2

[crude kraken]

mhm

[river garnet]

in your case though i don't know

[crude kraken]

captcha says that 3 was correct

so I guess that if we're not a computer, the answer is 3, but if we are, it's not 3

🤷

[river garnet]

haha

what if it's both

[crude kraken]

🤔

[river garnet]

or more importantly

neither?

[crude kraken]

😮

[prisma otter]

In the figure at right, BAD is a right angle, and C is the midpoint of segment AB. Given the dimensions marked in the figure, find the length of CD.

can someone help me out plz?

[crude kraken]

Do you know how to solve the triangle?

[prisma otter]

do i use the pythagorean therom?

[crude kraken]

That's one way of doing it

Do you know law of sines?

[prisma otter]

nope

[crude kraken]

Okay

Law of sines is

=tex \frac{sin(A)}{a} = \frac{sin(B)}{b} = \frac{sin(C)}{c}

[crude kraken]

where capitol letters are the angle, and lowercase letters are the opposite sides

So that means that to calculate the third side you need, you need angle C

[prisma otter]

so a would be 90 degrees?

[crude kraken]

To do that you need angle B

A is 90 and a is 26 and b is 24

[prisma otter]

ah