Answer:
∠ Y ≈ 32.7°
Step-by-step explanation:
Using the law of Cosines
cosY = [tex]\frac{x^2+z^2-y^2}{2xz}[/tex]
with x = 90, y = 55, z = 50
cosY = [tex]\frac{90^2+50^2-55^2}{2(90)(50)}[/tex] = [tex]\frac{8100+2500-3025}{9000}[/tex] = [tex]\frac{7575}{9000}[/tex] , then
∠ Y = [tex]cos^{-1}[/tex] ([tex]\frac{7575}{9000}[/tex] ) ≈ 32.7° ( to the nearest tenth )
