Question

Given the triangle below, find the measure of angle A . Picture is not drawn to scale

Answer 1

Answer:

A = 62.35°

A = 62° (Appropriately)

Step-by-step explanation:

To solve for the value of angle A, we employ the COSINE FORMULA.

cos A = (b² + c² - a²) / 2bc

cos B = (a² + c² - b²) / 2ac

cos C = (a² + b² - c²) / 2ab

Where:

A,B,C are the angles of the triangle.

a,b,c are the lengths of the sides

a= 20

b= 16

c= 21

Cos A = (16² + 21² - 20²) / 2*20*16

Cos A = (256 + 441 - 400) / 640

Cos A = 297 / 640

Cos A = 0.464

A = 62.35

A = 62 Appropriately.