Geometry

Question Analysis

The main focus is on using the property that an inscribed angle in a semi - circle is a right angle and the angle - sum property of a triangle. 

 

Key Concept Explanation

1. Inscribed Angle in a Semicircle: An inscribed angle subtended by a diameter (in a semi - circle) is a right angle, measuring .

2. Triangle Angle - Sum Theorem: The sum of the interior angles of a triangle is .

 

Step - by - Step Solution

1. Since is the diameter, in .

We know and .

2. Using the triangle angle - sum theorem (),

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