Question

Please help using law of cosines!

Answer 1

Answer:

∠ A ≈ 48°

Step-by-step explanation:

Using the Cosine rule to find an angle

cosA = $\frac{b^2+c^2-a^2}{2bc}$

with a = 10, b = 13 and c = 11

cosA = $\frac{13^2+11^2-10^2}{2(13)(11)}$

         = $\frac{169+121-100}{286}$

         = $\frac{190}{286}$ , thus

A = $cos^{-1}$ ( $\frac{190}{286}$ ) ≈ 48° ( to the nearest degree )