### Home > CCG > Chapter 5 > Lesson 5.3.5 > Problem 5-128

5-128.

In Chapter 1 you learned that all rectangles are parallelograms because they all have two pairs of opposite parallel sides. Does that mean that all parallelograms are rectangles? Why or why not? Support your statements with reasons.

Do all parallelograms have four right angles?

Try drawing a parallelogram that does not have four right angles,

if you can this is a counterexample.