#geometry-and-trigonometry
1 messages · Page 187 of 1
i like proofs
oh
but 2cols are shit
So are these right?
I have other options to switch in as well
first one might be corresponding
but idk
I usually use the corresponding and interior postulates in transversals
seems right
oh really
shit i never get these right
alrighty well
you know the rest of the drill,
3 more 😛
i'm not native so i actually suck at understanding geo in english
shit
hmm well I'll take the risk
m<d + <dab = 180
consecutiveeeeeeeee
oh shit
96 + dab = 180
=84
reeeeeeeee
cmon octoniion
only 2 more
this and one more
Real proofs are a thing of beauty. 2 column proofs are one of the worst things that will ever happen to anyone ever. Just putting my opinion out there
yeah.....
AE = CE
As E is the midpoint between A and C
How does she know the coordinates of the midpoint of BD are the same as the midpoint of AC?
Sounds like she should be trying to prove that, not assume it
jesus christ im dumb
yeah
it'd be AE
its right there too haha
could you check one that the other did wasn't good at?
this one
its fine
I got 100
Nice nice
hi
" If: sin (a) = 0.6 , So: sin (360° - a) = -0.6 "
that is true or wrong?
I answered "true" but its seems to be wrong
and i dont understand why...
that is true
sin(-a)=-sin(a)
since sine is an odd function
and since the period of sine is 360
sin(360+a)=sin(a)
"sin(360+a)=sin(a)" That is completlly understoood
yes
youre not wrong
I asnwered "True"
what
a-360 == a
that isn't my question sir
that is NOT prove that if sin(a) = 0.6 so sin(360-a) = -0.6
that is different cases
im gonna get there
dont worry
first
do you agree that sin(360-a)=sin(-a)
just answer this
but why do you do it in this way its very complicated
how is it complicated?
yes but why
well you're asking the question ? 
so why do you have to say the -sin(a) = sin(-a)
?
that is true but not answering the qestion
if sin(a) = 0.6
yes
where are the steps
and i didnt used: sin(-a) = -sin(a)
sin(a) = 0.6 ----- Data
sin(-a) = -0.6
sin(-a) = sin(360-a)
SO sin(360-a) = -0.6
perhaps
thats exactly what i did but in different order
ok
so are you sure that the book is wrong and not me sir?
cause i tried to understand for 4 hours why i wrong
i was sure that I understood everything after learning that for alot of hours and then this question made me think that all this was spent of time
and i dont understand anything
what does the book say
@dire rampart
the book say that the answer is wrong
that " If: sin (a) = 0.6 , So: sin (360° - a) = -0.6 " is Wrong.
I think there is another mistake sir
but im not sure
the book say also
"If A - B = 180" so "sin A = sin B " is Wrong.
but I say its true
who is wrong me or the book??
A = 270 B=90
sin(A)=1 sin(B)=-1
unless 1=-1 you're wrong
😬
actually I wrote that backwards sin(270)=-1 and sin(90)=1
I'm really bad at geometry, can someone help
In a triangle ABC with <ABC=90, point K lies on AB. Point L is chosen on BC such that CL=AK. Point M is chosen on AC such that KM=ML. If <KML=90, prove that AK=KM=ML=LC
I've tried drawing all types of constructions, I know that MLCK is cyclic but I can't really abuse that, and I think we might be able to do this through some form of Thales'.
<@&286206848099549185>
@droreh#9503 book is wrong for the first one but right for the second

@woeful flame
Can anyone help?
State your problem and we shall see
@upper karma I stated it above
CyriusToday at 7:23 AM
I'm really bad at geometry, can someone help
In a triangle ABC with <ABC=90, point K lies on AB. Point L is chosen on BC such that CL=AK. Point M is chosen on AC such that KM=ML. If <KML=90, prove that AK=KM=ML=LC
CyriusToday at 7:36 AM
I've tried drawing all types of constructions, I know that MLCK is cyclic but I can't really abuse that, and I think we might be able to do this through some form of Thales'.
CyriusToday at 7:45 AM
<@&286206848099549185>
hey guys i have this
tan(2x) - tanx = 0
i end up getting this
(tanx+tan^2x) / (1- tan^2x)
:/
@thin wasp Dude are you here?
Ig not.
@stable tusk If you'd like you can use #help-4
Or beta
Basically any room that is not currently being used.
Ok, tell me
what is the proof of a square?
How do you deduce that a quadrilateral is a square/
If all angles are 90 degrees and all sidelengths are the same
Yeah so basically it's a rectangle with 2 adjacent sides equal
So since KMLB has that property
It is a square
It might look werid
Just because opposite angles are both 90 doesn't mean its a square
Yeha
Can I ping someone else
But I'm really curious what you learnt at school about geometry
If you think that's a square
@little osprey The problem is, you're assuming KMLB is a rectangle when it isn't
You can’t assume that it is a rectangle. It looks like a right triangle but it very well could be at 91 degrees or 89 degrees. There is no right angle marking that would prove that it is a right angle
@atomic geyser Can you help with the problem?
And it is a right triangle by the problem statement
But BLMK is simply cyclic with <LBK=<LMK=90, not a rectangle
Is this trig? I’m not in it until January-February
No?
wtf did i just see someone try to call that a square
all sides need to be equal and it doesnt even remotely
Well you can see:
<MKA + <CLM = 180°
and that
<AMK + <LMC = 90°
Does that help anything
Then you could flip those triangles around
and see that all those sides are same
because those are always true:
<MKA + <CLM = 180°
<AMK + <LMC = 90°
um
From the problem statement
BLMK angles are 360° and <KML = 90° aswell as <LBK = 90°
So they will be supplementary
in all cases.
Helped @thin wasp
?
I don't follow
BLMK has four angles so their sum is 360°
KML and LBK are given 90°s
so only ones left are the supplement angles MKA and CLM
well
the adjacent ones
but you can flip around and they still equal 180° in total
Uh
What have you actually proved
I follow all of your statements about the angles
But i don’t see how you’re using that to prove the question @grim sorrel
No, why?
Just by the definition of those angles you can see (by moving the triangles together) that AKM and LMC always form a right triangle if you move the asked sides together ML to AK or MK to LC (Maybe also mirroring triangles)
just curious
also what are you trying to prove and what are you given?
um
module
question
why do you keep switching the angle letters to the point where the actual angle is different?
like cla and alc are the same but you're switching the middle letter too...
Not angles those are triangles
In a triangle ABC with <ABC=90, point K lies on AB. Point L is chosen on BC such that CL=AK. Point M is chosen on AC such that KM=ML. If <KML=90, prove that AK=KM=ML=LC
how does that prove its 90 degrees
@torpid horizon
You can get all the angles just from the Problem statement really
after you know those two are 90
I mean of course not exact values but that which ones are supplementary or complementary
Ok so once you know those angles add up to some number
You can make a new triangle by joining them
How does that prove that they are isosceles?
<KAM + <MCL = 90°
<LMC + <AMK = 90°
<MKA + <CLM = 180°
<BKM + <MLB = 180°
never
mind
it is not perpendicular
module
do you know how euclidean geometry works
?
Tell me
Well triangle has angles sum to 180 and <CBA = 90
youre basically telling me
sooo
angle A and angle C of the two triangles is forming a irght angle
Yes yes
@grim sorrel I agree with all your angle identities, I don’t know how you use it to prove the question
I didnt
I havent randomly assumed anything
Yes it was
It is in the problem statement that <ABC = 90°
well
Ah that I didnt know
@duck#7999 Olympiad geometry probably differs American curriculum geometry
do you use proofs in it
@grim sorrel you reflect m over l
What
You’re given that certain angles are 90 degrees
Give me a moment
thats why i asked you if this was a question your geometry teacher gave you
i see
Stuff like q9
This isn’t like the American system (I think?) where you mindlessly bash out “proofs” about angles being equal by some arbitrary postulate
euclidean geometry is pretty much accepted everywhere tho
i believe it was the basis for all geometry
The harder path is trying to find what constructions/modifications you can make
they are assumed but they havent been disproven
and most of them are theorems btw which are proven
You’re getting into a different area
Their only ‘proven’ because of assumption
I have to go for now
@thin wasp
yes
but geometry is all based off assumption...
and i mean the beginnings
which are the planes
lines
i forgot the rest
but after those assumptions everything else can be proven
if you want to take the perspective with geometry as that everything is based off assumption, so is science.
everything is based off something that was assumed and then was expanded
@quaint ruin
right angle congruence theorem is if two angles are right angles then they are congruent
But I'm trying to prove the 2 triangles are congruent
So what should I do instead if it's wrong?
Its given already
so like de equals eb
oh okay
Fml
umm
U should go with vertical angkes
im no help sorry 😦
i failed geometry
Use whatever tool you like best to graph the function.
Look at what the function does as x approaches the 2 points from either direction.
It says you can use a graphing utility to graph the function.
I assume you're working on 56, with secant.
Use your favorite graphing tool, Desmos, Geogebra, TI-83/84/89/Inspire, whatever you'd like, to graph sec(x).
Look at what the y-value does as x approaches the two values in the question from either direction.
It's asking you where the graph goes as x goes towards the 2 given values from the left or right.
so
what should my answer look like?
As x approaches 0 from the left
It goes to - infinity
As x approaches 0 from the right
It goes to +inf
Just as an example.
why is tan(30) a negative number? Im trying to make Nicolas Cage Pong and the camera should be at an angle of variable angle and at a distance of variable Distance but the sphere should be at the centre of the screen, meaning that I have to set my y axis high enough to do so. So I made Distance 10 and angle 30, which should mean the y axis should be 5.77, but it was -6.57.
*note that this is in radians.
does that mean the a my answer shouldn't be tan(angle) * distance?
I think you may want to find out where the camera is initially pointing
I used Debug.Log(tan(angle)) and it returned -6.57
its rotation starts at 0,0,0,0
@spare garden do you still need help?
yes
Wait
I also want to know how I can position my camera properly
Uhh
I don’t know much about camera positions, but tan(30) shouldn’t be negative
But it is
Which is weird
Are you in degrees or radians?
What calculator do you have
Yeah, that makes sense
switch to radian?
Yes
Mrcuddles wants to know why
But I’m confused myself
Tan(30) shouldn’t be negative
It’s in the first quadrant
Ohhhhhhhh
I’m so dumb
...
No ur not dumb
@spare garden
So the reason for this is is 30 radians is about 1718 degrees
That amount is in the fourth qurasrant
That means that any tangent in the fourth quadrant is going to be negative
What else do you need help with
I need help with 16
Im just guess and checking
my eocs are next week im panicking so much
Eoc?
End of course
like finals
but
we have 2 finals
One is state required
And the other one is also state required but the teacher makes it
stupid education
From SOHCAHTOA, we know that the sine of an angle will yield the ratio of opposite/hypotenuse.
Furthermore, we know the hypotenuse is the longest side of a right triangle.
Can you show me your process Mr cuddles
uhh
Wake
Wait
I thought I was helping you but I’m helping @quaint ruin
Do you have any work to show for how you got the answer Gary
Hmm
nop
I think i have to use laws of sines
but i pretty much frogot that
My schedule atm
:/
Rip in biology
I mean
Its only one unit
In ecology
the only promblem
My teacher loves to put trick questions
@quaint ruin okay I figured out the problem
I honestly gave up on life 😦
No no
im about to go mental
It says that the sine of an angle is .28
What is sine? It’s just opp over hypotenuse
yea
All the opp sides are the first numbers and the hypotenuses are just the last numbers
Oh
yes
then use it lol
ok nvm
you don't need to remember them like in organic chem tho
you just need to be familiar with them
Ohhhh fuck
Don’t say that my dude
If you ever plan on taking calculus at least
When you take calc, you use everything
Im taking calc next semester
HAHAHAHAHAHAHA calc will fuck anyonw with that attitude
Algebra2/Pre Calc
it will make u your bitch
im only in 9th grade dude
Not precalc
HELP ME
precalc is easy
i have to
Take trig
jsut limits and continuity
Im doing that rn
Wait
its with geometry
Really??
you guys had choices lul
You don’t need a whole course for that
I learned about triangles
it was shoved down my throat
fml
Calc isn't that bad, just make sure you understand the proofs in class/books, and do lots of examples o:
Who takes an entire course with just that
Yeah, take trig
hehehehehe
already took it
It’s extremely important
its with geometry
What?
Im taking it rn
As a separate class?
no
In conjunction with geometry?
someone saying calc is easy is either doing masters or he hasn't faced off against real calc yet
yes
As like a separate semester?
Are you sure?
pretty much Indian education system
What’s the unit circle
uhh
because that’s literally all of trig
circle...
im learning that rn
Sooo
i havent learned that
i have learned radians arcs and shit
of circl
unit = 1
That’s geometry
unit circle = circle with radius 1
Alright, let me give you a crash course in trigonometry
You have a circle with a radius of 1
Divide it into 4 quadrants
Like a graph
Only a circle is surrounding it
t!wiki unit circle
@upper karma
Yeah
Does your class say trig/geometry
Because they really should be two separate classes
~~also skip precalc there’s nothing you need to know that’s important in precalc
You’re British?
British literature?
You should take trig instead of precalc
idunno the school system is so broken
Are they forcing you to take precalc or can you skip it
You should see if you can take trig instead
Go up to the office or ask a teacher that teaches it
maybe
If not, precalc is the class you need
Because you do you a lot of trig
And algebra
we have to take 8 ap classes
ugh
and the rest are honors
why did i put myself
in this position
8 in total or in one year
total
Just take 3 sophomore 3 junior and 2 senior
Im taking ap human geo
Human geo?
Sounds boring
?
No I’m from Nigeria
Nah I’m kidding
flawed
Well, best of luck to you
At least get a high school diploma
If you don’t go to college, fine, but keep the option open for yourself
i already got pre-acceptance into colleges
How
SAT ig
SAT freshman year?
Interesting
my guessing skills are on fleek
I have much to learn about the art of guessing
so
whenever they give u
like
solve for AB
and there is an x
just plug each one in
as x
and see
which one u get
and one ususally is x and outcome is the answer
I need an actual example from a problem
-10
plug each answer in
Too much time
no
It’s easier to just solve for it
If they ask for the answer, it’s stil quicker to solve
hmm
i mean it might be
but when u are doing complicated promblems
and sat is timed
fuck time
it goes too quick
u dont have time to solve all those shits
lol
Each day is like 36 hours
Bye
Cali
What time is it for you
,time
The current time for Garyxue213 is 1:21 AM (EST(-0500)) on Fri, 30/11/2018
!
You haven't set your timezone! Set it using ,time --set <timezone>!`
Volume of room ÷ Volume of 1 basketball
Ok sure by why?
Ping?
Also it's wrong because you need to take the CUBE of one diameter
If you get what I mean
There would be left space
It isn't wrong if you can understand what I said.
Volume of one basketball is different from volume NEEDED to FIT one basketball.
Your statement is not very precise

So it's volume of room / diameter^3
To be exact
theres nothing wrong with what manis said
assuming ofc the balls are inflated
which i guess is a reasonable assumption to make
^
There would be leftover space between each ball
So we would have to take a cube
Whose side legnth would be the same as that of the ball's diameter
Unless they do shit like this
Oh no
Rather than stacking them on top of each other
Technically both of you are wrong if they pull that off
its fine, question probably assumes they're tightly packed anyways
guys
given 2 points on a random window
how should i choose the third so that the circle defined by those 3 points isnt bigger than the window size?
put them close to colinear
oh wait
you want it smaller, so make them in like an equilateral triangle or something
aint angle dce = angle fbe by the angles in the same segment theorem so that proves all angles are same so it must be congruent
im not sure if u can say they are in the same segment though
actually yea they must be --> coming off the fe chord
how will two rays, facing opposite directions, intersect
or are they parallel because wouldnt they have the same slope?
ok so
does anyone have a compiled list of goemetry theorems
cause @lament bay needs help with learning them
uh
wait actually
i might have somehting oof
one minute
Start studying Geometry Theorems. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
yeah ok thats what my teacher gave at a final review thing
and told us to study the ones we didnt know
and make flashcards
legit math theorems just sometimes have to be memorized @lament bay but I do recommend when learning them to think about the name of the theorem and relate it to what the theorem actually states
hello
I'm trying to solve this equation in [0;2pi]
4 cos^4(x) - 11 cos^2(x) + 6 = 0
if I declare X = cos^2 (x), I can solve it with 0.75
how can I find all the solutions?
<@&286206848099549185> any ideas?
@keen aspen I nearly finished but I'm stuck with cos x = sqrt(0.75) or sqrt(-0.75)
I can't get the exact values of these (with pi)
You can
Ok cool how?
Okay well its 30
Thx for helping+
Np
Easy question:
So, the line ABE is straight and the ratio between AB and BE is 3 : 2
AB is equal to a.
How do I work out the length of BE?
I was thinking that a is 3/5 of the whole length, so... yeah
AB/BE = 3/2
a/BE=3/2
BE/a=2/3
BE=2a/3 @stark snow
hoihoihoi
What’s up squad it’s Young don the sauce god
Neat
there's 2 wrongs in this q
d is only true if you have a square yeah
so its just C?
is ABC
B is ofc true cause that's the def of a rectangle
cause of it creating a triangle?
cause of the parallelogram forms two triangles from the diagonals its a rectangle
+the diagonals have equal lengths in a rectangle (+ the diagonals both cut at their middle cause parallelogram)
so if you take any two half-diagonals in a rectangle, their lengths will be equal
wtf is cpctc?
LOL
corresponding parts of congruent triangles are congruent
I don't understand it fully
but it seems like the only obvious choice out of HL congruence and transitive
not transitive at alla nyways
and waht's HL?
I've been seeing throughout the lesson of them just using the cptc in the last box
dude idk lol
hypotunuse i think
lemme see
ahh hypotenuse leg
The hypotenuse leg theorem states that any two right triangles that have a congruent hypotenuse and a corresponding, congruent leg are congruent triangles
those are right triangles soooooooo out of the question
Idk if the first one is right
cause AD and BC are opposite
but so is AB and DC
hellow
seems roight
but screw 2cols anyway
at least when you get to do your own from scratch it's ok
but completing a 2col seems like pure bullshittery to me
lol
Its gonna be on the state exam that I gotta pass to graduate :PPPP so I gotta love it
6y - 5y = 10
y = 10
yas
yas

Hello : ) I am trying to solve a real world problem. I have a round disc measuring 380mm across, but it has a radiused edge, or fillet, applied to the circumference. With the added material and at the widest point, the diameter becomes 386mm. The pic below shows what I am talking about. Is there a way to calculate the actual radius of the fillet applied to the circumference, or r?
note that the fillet is not semi-circular, so I guess this is an arc length problem ... its been years since i did geometry though : (
do you know the width of your 'plate'?
yeah, 18.5mm : )
its one of these 🤣
i'm using it as a temporary base for a robotics experiment and need to 3d print two clamps either side which will allow me to attach shelves for sensors. I could just have the clamps be normal tangent to the fillet, but would prefer a more 'positive' match for the inside of the clamps to the fillet. I could just do it vaguely, but wheres the fun in that
like so
i trundled through some sin and cosine rule, bit of pythagoras, but theres too many unknowns
my other option is to 3d print a bunch of known radius arcs and see which one fits
if you literally have the 3D model on your computer, use boolean modifiers to take the difference a shape at the edges there to make your clamp specifically around the shape there
sadly that model is one i made, just an approximation
if you apply pythagoras in CMO you get MO²+CO²=CM², or (9.25)²+(h-3)²=R²
if you apply pythagoras in CMS, $ MS²+CM²=CS²$, or $$\sqrt{3^2+9.25^2} + R^2 = h^2$$
emeric75:
2eq, 2unknowns

one question, might be a dumb one ... how can we be sure that M is a right angle?
shit idk how it's called in english
hha ok not to worry : ) Many thanks for your help, its super appreciated!
x+1?
in terms of y and z
What's z
y = 1y + 0z
Lmfao
can anyone here help me with some simple trig
triangle that has 2 known sides = 10root3 and 6 with an angle of 60 inbetween
i need to find the length of the third side
I tried using cosine but my answer came back as wrong
should work
I got approx. 232.08
maybe your calculator was set to radians
?
unless you didn't mean you used the cosine rule
hey guys
I have this equation : cos(x) = sqrt(75) or -sqrt(75)
and I would like to find its solutions in [0;2pi]
