Question

In triangle ABC, the length of side AB is 12 cm, the length of side BC is 5 cm, and the length of side CA is 9 cm. Find the measure of angle A using the law of cosines.

Answer 1

Answer:

22.20 is the correct answer! Hope I helped.

Answer 2

The measure of angle A is 22.19°.

What is a Triangle?

A triangle is a polygon with three sides, vertices, and angles.

The length of the sides of a triangle ABC is

AB = 12 cm

BC = 5 cm

CA = 9 cm

The angle of the law of cosines has to be used to determine the value of angle A

b² = a²+c² - 2 ac cos A

Substituting the values

5² = 12² + 9² -2 * 12 *9 cos A

cos A = 0.9259

A = 22.19°

Therefore, the measure of angle A is 22.19°.

To know more about Triangle

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