Question

It would be great if i can get some help. Thank you. Include explanation please

Answer 1

We're given two sides and the included angle and asked to find the third side. That's the Law of Cosines.

$c^2 = a^2 + b^2 - 2 a b \cos C$

$c = \sqrt{15^2 + 20^2 - 2 (15)(20) \cos 50^\circ} \approx 15.5 \textrm{ feet}$