Question

when is a rhombus a square?
a. when its angles are right angles
b. when its angles are convex angles
c. when its sides are parallel
d. when its sides are congruent

Explanation:

A square is a special type of rhombus. A rhombus has all - sides congruent. A square has all - sides congruent and all angles are right angles. When the angles of a rhombus are right angles, it meets the definition of a square. Convex angles are not specific enough to make a rhombus a square. Sides being parallel is a property of both rhombuses and squares but not what makes a rhombus a square. Sides being congruent is a property of a rhombus already.

Answer:

A. When its angles are right angles