Answer:
A parallelogram whose four angles are congruent is rectangle
Explanation:
Given that a parallelogram has four congruent angles.
we have to choose the best name which describes the figure.
A parallelogram is a quadrilateral with opposite sides parallel and equal.
As all the four angles are congruent which means all the four angles are equal.
Let the measure of congruent angle is x
By the angle sum property, the sum of all angles of quadrilateral is equal to 360°
⇒ x+x+x+x=360


Hence, the measure of all 4 angles of Parallelogram is equal to 90°
From the given figures the rectangle is the only figure in which the measure of all angles 90°. Opposite sides of rectangle are parallel and equal.
∴ A parallelogram whose four angles are congruent is rectangle