Question

Besides the 90° angle measure, what are the other two angle measures of a right triangle with side lengths 5, 12, and 13? Round to the nearest degree.

18° and 39°
23° and 67°
43° and 47°
65° and 25°

Answer 1

Use a trig ratio. With hypotenuse 13, the angle opposite side 5 is sin⁻¹(5/13) ≈ 22.62° ≈ 23°, and the other acute angle is 90° − 22.62° ≈ 67°.

Answer: 23° and 67°.