Geometry

Question Analysis:
This question tests understanding of: The angle-sum property of triangles.
Corresponding parts of congruent triangles (CPCT).

Key Concept Explanation:
Congruent triangles have equal corresponding angles and sides.
The sum of angles in any triangle is 180∘.
Vertex correspondence in congruent triangles follows the naming order:
X↔P
Y↔Q
Z↔R

Step-by-Step Solution:
Find ∠Z in △XYZ:
∠X + ∠Y + ∠Z = 180∘
50∘ + 60∘ + ∠Z = 180∘
∠Z = 180∘ − 110∘ = 70∘
Apply CPCT (Corresponding Parts of Congruent Triangles):
Since △XYZ≅△PQR, their corresponding angles are equal: ∠...