Square PQRS: Find ∠SRP (angle at R between side RS and diagonal RP).

Introduction / Context:
In a square, the diagonal bisects a right angle at each vertex, creating 45° angles with the sides.

Given / Assumptions:

• PQRS is a square; diagonal considered is RP.

Concept / Approach:
Interior angles of a square are 90°. The diagonal from a vertex splits the 90° into two equal 45° angles.

Step-by-Step Solution:
At vertex R, the diagonal RP bisects ∠QRS = 90°.Therefore ∠SRP = 90°/2 = 45°.

Verification / Alternative check:
Coordinate square of side a: slope of RS is 0, slope of RP is ±1; angle between them is 45°.

Why Other Options Are Wrong:
90° would be the full corner angle; 60°/100° do not occur in a square’s diagonal geometry.

Common Pitfalls:
Mixing up which angle at R is asked; it is the angle between side RS and diagonal RP.

Final Answer:
45°