1. What property do ALL quadrilaterals have?

They all have 4 sides

2. Do any of the common quadrilaterals have zero axes of symmetry?

The parallelogram has 0 axes of symmetry.

3. Which quadrilaterals have diagonals that intersect (cross) at right angles?

Kite, arrowhead, rhombus and, of course, the square.

4. What is the similarity between an rhombus and a square?

They both have 4 equal sides and diagonals that cross at right angles.

5. What is the similarity between a rhombus and a parallelogram?

They both have opposite ANGLES equal and opposite SIDES are parallel.