Decide if the following statements are true or false. If a statement is false, provide a diagram of a counterexample.  

1. All squares are rectangles.

   Answer (a):

   True, a rectangle is a quadrilateral with four right angles and a square is a quadrilateral with four right angles and four congruent sides.

2. All quadrilaterals are parallelograms.

   Answer (b):

   False, quadrilaterals can exist without parallel sides, like a kite or a trapezoid.
   Remember a parallelogram has 2 sets of parallel sides.

3. All rhombi are parallelograms.

4. All squares are rhombi.

5. The diagonals of a parallelogram bisect the angles.