Geometry

Question Analysis

The main focus is leveraging the tangent - radius perpendicularity and triangle angle - sum properties. Since  is tangent to , . Given , we'll use the angle - sum property of a triangle to find .

 

Key Concept Explanation

A tangent to a circle is perpendicular to the radius at the point of tangency, making . In , we apply the angle - sum property () to determine .

 

Step - by - Step Solution

1. Recall the angle - sum property of a triangle: .

2. Substitute