Question

A parallelogram with congruent diagonal is a ______.

Short answer

Rectangle.

Step-by-step solution

Step 1. Given information.   

The given statement is “A parallelogram with congruent diagonals is $\underset{¯}{}$”.

Step 2. Concept used.

A parallelogram has two pair of opposite sides parallel and equal.

Step 3. Soluton.

A parallelogram has two pair of opposite sides parallel and equal.

When diagonals are equal, then it becomes rectangle.

A rectangle has diagonals equal in length and they bisect each other.

Therefore, the blank is filled with term Rectangle.