Finding a missing angle, step by step

When both legs — or a leg and the hypotenuse.

Practice Practice sheet New questions

The question

degrees

Find the angle: opposite 13, adjacent 4

tan x=13 ÷ 4

x=tan⁻¹(13 ÷ 4)

x=73°

You know the two legs: the side opposite the angle is 13, and the side next to it (adjacent) is 4. Opposite over adjacent is the tangent.
To undo the tangent, use inverse tangent (tan⁻¹ on the calculator): x = tan⁻¹(13 ÷ 4).
That is 73° to the nearest degree.

How it works.

01
You know the two legs: the side opposite the angle is 13, and the side next to it (adjacent) is 4. Opposite over adjacent is the tangent.
02
To undo the tangent, use inverse tangent (tan⁻¹ on the calculator): x = tan⁻¹(13 ÷ 4).
03
That is 73° to the nearest degree.