Answer:
D) 53.5°
Step-by-step explanation:
Sine and cosine of complementary angles are equal:
sin θ = cos(90 − θ)
sin(x/2 + 20) = cos(2x − 25/2)
cos(90 − (x/2 + 20)) = cos(2x − 25/2)
90 − (x/2 + 20) = 2x − 25/2
90 − x/2 − 20 = 2x − 25/2
165/2 = 5x/2
5x = 165
x = 33
x/2 + 20 = 36.5
2x − 25/2 = 53.5
Since β > α, β = 53.5°.