Question

How to find the area of:

Answer 1

top side is 9cm, bottom side is 10cm, and the angle in between is 40 degrees

Answer 2

Law of cosines
a^2 = b^2 + c^2 -2bc*cosA

Answer 3

a = sqrt (181 - 180 cos A)

Answer 4

right...so far I have, A=1/2absinC
1/2x9x10xsinC
45sinC

Answer 5

but I'm stuck there...

Answer 6

Where is the 1/2 coming from? There are like 3 different law of cosines, but the angle you were given and the side across from it is missing, so that is why I used the one I gave you

Answer 7

Law of cosines
a^2 = b^2 + c^2 -2bc*cosA

Answer 8

I'm using law of sines

Answer 9

First, I would find the side of A...

from there you drop the altitude down and take 1/2 of A

Answer 10

ok, thank you!

Answer 11

I would prefer to use the law of cosines... sqrt (181-180cosA) = 6.57 approx (so that is the value of A

Answer 12

1/2 of A is 3.285

Answer 13

using Pythagorean thereom the H is 9.4
now use A = 1/2 BH
a = 1/2 (3.285)(9.4)
area = 15.47