Geometry

Question Analysis:
This question involves the properties of congruent triangles.
The main focus is on using the fact that corresponding angles of congruent triangles are equal.

Key Concept Explanation:
When two triangles are congruent, their corresponding angles are congruent.
This is known as CPCTC (Corresponding Parts of Congruent Triangles are Congruent).
In this case, in corresponds to in .

Step - by - Step Solution:
1. Since (by SAS congruence as the side markings indicate), we know that (by CPCTC).
2. Given that and