Question

Find the angle which is four times its complement.

Answer 1

Let the measure of the required angle be $x$.
Then, measure of its complement $=\left(90°-x\right)$.
Therefore,
$$\begin{gathered} x=\left(90°-x\right)4 \\ \Rightarrow x=360°-4x \\ \Rightarrow 5x=360° \\ \Rightarrow x=72° \end{gathered}$$
Hence, the measure of the required angle is $72°$.