15 POINTS.LAW OF COSINES.ANSWER WITH EXPLANATION.ILL GIVE BRAINLEST

[tex]\text{Welcome!}\\\\\text{Your equation should look like:}\\c = \sqrt{a^2 + b^2 - 2 \a \ b\ cos Y} \\c = \sqrt{55^2 + 50^2 - 2 * 55 * 50 * cos (90 \ degrees)\\ \\\fbox{ c = 74.33034}\checkmark[/tex]
Answer:
∠Y ≈ 32.7°
Step-by-step explanation:
Using the cosine rule in Δ XYZ
cosY = [tex]\frac{x^2+z^2-y^2}{2xz}[/tex] ← substitute values
= [tex]\frac{90^2+50^2-55^2}{2(90)(50)}[/tex]
= [tex]\frac{7575}{9000}[/tex], thus
Y = [tex]cos^{-1}[/tex]( [tex]\frac{7575}{9000}[/tex]) ≈ 32.7°