Question

How do you solve the right triangle ABC given A= 40 degrees, C= 70 degrees, a=20?

Answer 1

`29.2`

Explanation:

Assuming that `a` represents the side opposite angle `A` and that `c` is the side opposite angle `C`,
Not drawn to scale!
We apply the rule of sines :

`sin(A)/a=sin(C)/c`

`=>c=(asin(C))/sin(A)=(20*sin(70))/sin(40)~=29`

Good to know :
Larger the angle the longer the side opposite to it.

Angle `C` is greater than angle `A`, so we predict that side `c` will be longer than side `a`.