Question

9^2= 9.5^2 + 4^2 - 2 (9.5) (4) (cosR) I'm trying to find out the angle measure of R

Answer 1

Sorry I can't solve it.

Firstly, the equation is wrong. It is supposed to be 81 ≠ 30.25

Second of all, this is the best I got 81= −76 (cos(r) + 106.25