Chapter 12.1, Problem 4C

To determine

To Calculate: The other angle of a supplementary angle pair when one angle is given.

Answer to Problem 4C

The measure of the angle that is supplementary to an angle measuring ${118}^o$ is ${62}^o$ .

Explanation of Solution

Given Information: Two angles are a supplementary angle pair and one of the angles measures ${118}^o$ .

Concept Used: If the sum of the measure of two angles is ${90}^o$ then the angles are called complementary angles and if the sum is ${180}^o$ then the angles are called supplementary angles.

Calculation: Since $\angle 1$ and $\angle 2$ are supplementary angles

  $m\angle 1+m\angle 2={180}^o$

  $\Rightarrow {118}^o+m\angle 2={180}^o$

  $\Rightarrow m\angle 2={180}^o-{118}^o=62^o$

The measure of the angle that is supplementary to an angle measuring ${118}^o$ is $62^o$ .

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