#missing length
plain horizon
unique spindle
Cosine rule 👀
sleek pendantBOT
iiiiiiiiiiiiii
atomic dust
so cool
atomic dust
it's a rule you use
when you don't have a matching angle and a matching length
(sine rule)
plain horizon
wdym matching angle
atomic dust
the angle here is 75* right
plain horizon
Yes
atomic dust
but there isn't a length opposite to it
and there are also no other angles so no other matching lengths
at that moment you'd use cosine
plain horizon
but there isn't a length opposite to it
what about matching lengths
unique spindle
If you have 2 sides and the angle between them you can work out the length opposite the angle
plain horizon
does that just mean a length is missing
atomic dust
does that just mean a length is missing
mhm
which is the length you're trying to find
AB
plain horizon
Ok thanks
atomic dust
**iiiiiiiiiiiiii**
use this ^
b and c are your 2 lengths that you already know
cosA would be cos(75) as 75 is your angle
just remember to squareroot your answer as it's a^2
north swan
@atomic dust don’t u have to rearrange it
To make it c^2=
Also what day is that
Of the 5 a day
atomic dust
<@1016001613678247977> don’t u have to rearrange it
no
north swan
aren’t u meant to find c
atomic dust
aren’t u meant to find c
no
b and c are the lengths you've got
a is the length you're trying to find
hence a^2 = b^2 + c^2 - 2bcCosA
north swan
a is the length you're trying to find
Sorry I’m just confused
Isn’t a 6?
And b 8
sleek pendantBOT
iiiiiiiiiiiiii
atomic dust
this is the formula for the cosine rule
what you're trying to find in that question is length AB
instead of a^2 you could just write AB^2 instead
$AB^2 = b^2 + c^2 - 2bcCosθ$
sleek pendantBOT
iiiiiiiiiiiiii
atomic dust
I thought opposite the capital is the lowrrcase
opposite the capital?
do you mean opposite of the angle
atomic dust
that's sine rule