Question

In right triangle ABC, angle C = 90 degrees. Angle A = 40 degrees and the length of the leg opposite angle B is 18 feet. Find the length of the hypotenuse to the nearest tenth.

Answer 1

The hypotenuse is 20 ft

Explanation:

• Step 1: This is a right triangle, so the trigonometric ratio cosine can be used to find the length of the hypotenuse. Given side opposite to ∠B, AC = 18 ft and ∠A = 40°,

cos 40° = adjacent side/hypotenuse = AC/AB = 18/AB

⇒ AB = 18/cos 40° = 18/0.76 = 23.5 ft ≈ 20 ft