91Ó°ÊÓ

$∠1$ and $15°$ are complementary angles.

If the sum of two angles is $90°$ then the angles are called complementary angles and if the sum is $180°$ then the angles are called supplementary angles.

Since $∠1$ and $15°$ are complementary angles.

$\begin{array}{c}m∠1+15°=90°\\ m∠1=90°−15°\\ =75°\end{array}$

The measure of the angle that is complementary to an angle measuring $15°$ is $75°$.

$∠1$ and $15°$are complementary angles.

If the sum of two angles is $90°$ then the angles are called complementary angles and if the sum is $180°$ then the angles are called supplementary angles.

Since linear angle measures $180°$. Thus, $∠1$ and $∠2$ are supplementary angles.

$\begin{array}{c}m∠1+m∠2=180°\\ 75°+m∠2=180°\\ m∠2=180°−75°\\ =105°\end{array}$

The measure of the angle that is supplementary to an angle measuring $75°$ is $105°$.