Question

the measure of an angle is 138°. what is the measure of its supplementary angle?

Explanation:

Step1: Recall supplementary angle definition

Supplementary angles sum to \(180^\circ\). Let the supplementary angle be \(x\). So, \(138^\circ + x = 180^\circ\).

Step2: Solve for \(x\)

Subtract \(138^\circ\) from both sides: \(x = 180^\circ - 138^\circ\).
Calculate the difference: \(x = 42^\circ\).

Answer:

\(42\)