Question

Can someone please answer. There is one question. There's a picture. Thank you!

Answer 1

By Cosine Rule:

CosT = (s² + r² - t²) /(2sr)

CosT = (10² + 11² - 7²) /(2*11*10)

CosT = 172 /220 ≈ 0.7818

T = Cos⁻¹(0.7818)

T ≈ 38.57°

T ≈ 38.6°