Question

Find the area of each triangle:

Picture below:

Answer 1

Using laws of sin and cos

Answer 2

\[\huge c^2 = a^2 + b^2 - 2ab \cos(C)\]plug in the points and solve

Answer 3

is the c with the 8.4 correct?

Answer 4

\[\huge c^2 = 8.5^2+12^2- 2*8.5*12\cos(21)\]

Answer 5

^^^ that is to find the c

Answer 6

So the formula is 1/2absinC?

Answer 7

I plugged that in and got 327.98. The square root would be 18.1?

Answer 8

Wait my formula of area of tris says: 1/2absinC >>> Wouldn't the formula just be 1/2x12x8.5xsin21 ?

Answer 9

c^2 = 216.25-204*0.83358
c^2 = 25.7995
c = 5.079