Question 472082
If a parallelogram has one right angle, then the other angles are right angles (since the opposite angle is equal and the adjacent angles are supplementary).


So there are 4 right angles. Since we have 4 right angles and 4 congruent sides, we have a square.


So...


A parallelogram is a <u>square</u> if and only if it has at least one right angle and four congruent sides


making the answer choice B.