Work Step by Step
A square is a parallelogram, so if two consecutive sides are congruent, their opposite sides are also congruent, meaning all sides are congruent. One angle of the quadrilateral is marked as a right angle, so its consecutive angles also must be right angles because consecutive angles in a parallelogram are supplementary. Its opposite angle, which is congruent to it, is also a right angle. Therefore, this quadrilateral has four right angles. This is a diagram of a square, which has all congruent sides and four right angles.