Question

if ∠abc and ∠def are supplementary, and m∠abc is equal to 45°, then what is m∠def? m∠def = ？°

Explanation:

Step1: Recall supplementary - angle definition

Supplementary angles add up to 180°. So, \(m\angle ABC + m\angle DEF=180^{\circ}\).

Step2: Substitute the given angle value

Given \(m\angle ABC = 45^{\circ}\), then \(45^{\circ}+m\angle DEF = 180^{\circ}\).

Step3: Solve for \(m\angle DEF\)

\(m\angle DEF=180^{\circ}- 45^{\circ}=135^{\circ}\).

Answer:

135