Question Analysis
This question combines the geometric concept of an angle bisector with algebraic equation - solving.
Key Concept Explanation
An angle bisector is a ray that divides an angle into two equal - measure angles. So, if bisects , then , and .
Step - by - Step Solution
1. Set up the equation based on the angle - bisector property:
Given and , we can write the equation .
Simplify the left - hand side: .
2. Solve the equation for :
Subtract