75 = ( 50^2 /16) * sinθ cosθ
75 * 16 / 50^2 = sinθ cosθ
12/25 = sinθ cosθ
Note that sinθ cosθ = sin 2θ / 2
So....mutiplying both sides by 2 we have
2 * 12 / 25 = sin 2θ
24 / 25 = sin 2θ
Note arcsin ( 24/25) ≈ 73.74°
Dividing this angle in half we get that θ ≈ 36.87°