# Square - ness of Parallelograms

- Author:
- Judah L Schwartz

- Topic:
- Parallelogram, Square

A rhombus is a parallelogram with perpendicular diagonals that in certain circumstances is a square.
A rectangle is a parallelogram with interior right angles that in certain circumstances is a square.
Can you devise a measure of squareness of parallelograms that allows you to tell how much "squarer" one parallelogram is than another?
Can you devise a second and different measure of squareness of parallelograms? Under what circumstances might one such measure be preferable to the other?

**What questions could / would you put to your students based on this applet ?**