The sides and angles of a right triangle are labeled.

Question

Use the inverse of cosine to find the indicated missing angle. Round your answer to the nearest tenth.

Answer 1

In a right triangle, we have:

Side opposite the angle: 10
Hypotenuse: 15

We want to find angle A, which is opposite to the side with length 10.

Using the definition of cosine:
cos(A) = adjacent / hypotenuse
cos(A) = 10 / 15
cos(A) = 2/3

To find angle A, we take the inverse cosine of 2/3:
A = cos^(-1)(2/3)
A ≈ 48.2 degrees

So, the missing angle A is approximately 48.2 degrees.