Question

Find the measure of an angle that is 25° less than its supplement.

Answer 1

Let the measure of the required angle be $x$.
Then, measure of its supplement $=\left(180°-x\right)$.
Therefore,
$$\begin{gathered} \left(180°-x\right)-x=25° \\ \Rightarrow 2x=155° \\ \Rightarrow x=77.5° \end{gathered}$$
Hence, the measure of the required angle is $77.5°$.