Geometry

Question Analysis

This question involves the concept of supplementary angles.

 

Key Concept Explanation

Supplementary angles are two angles whose sum is equal to 180°. When two angles are placed next to each other to form a straight line, they are supplementary.

 

Step - by - Step Solution

1. Set up the equation based on the property of supplementary angles:

Since the angles and are supplementary, we can write the equation .

 

2. Isolate the variable :

First, subtract 84 from both sides of the equation: