What do we call a quadrilateral with 4 congruent sides and 4 congruent angles?

A quadrilateral with four congruent sides and four congruent angles is defined as a square. This specific type of quadrilateral has all sides equal in length, which is a property it shares with rhombuses. However, what uniquely characterizes a square is the presence of right angles (90 degrees), making all angles congruent as well.

In contrast, a rectangle has opposite sides that are equal, but does not necessarily have all sides congruent. While a rectangle has four right angles, it fails to meet the criterion of having all sides be the same length, which is essential for a square. A trapezoid features only one pair of parallel sides and neither defines congruence of sides nor angles. Lastly, a rhombus possesses four equal sides but does not require right angles; thus, its angles may not be congruent. Therefore, the fact that a square satisfies both conditions of having congruent sides and angles makes it the correct answer.