Question

Determine the measure of the indicated angle in the following triangle:

Answer 1

Answer:

Θ ≈ 58°

Step-by-step explanation:

using the Cosine Rule in the triangle

cosΘ = $\frac{80^2+60^2-70^2}{2(80)(60)}$ = $\frac{64000+3600-4900}{9600}$ = $\frac{5100}{9600}$ = $\frac{51}{96}$ , then

Θ = $cos^{-1}$ ( $\frac{51}{96}$ ) ≈ 58° ( to the nearest degree )