Rectangles Activity
Notes on Squares

 A rectangle is a parallelogram with right angles.

Hand each student a ruler.

Tell the students to find a rectangle that is close to them.  (sheet of paper, book, dollar bill, library card, etc.)  Measure both diagonals of the rectangle.

Ask students to share the measures of their rectangles.

What can you conclude about the diagonals of rectangles?
The diagonals of a rectangle are congruent.

What other properties does a rectangle have?
Since a rectangle is also a parallelogram, opposite sides are congruent, opposite angles are congruent, consecutive angles are supplementary, and the diagonals bisect each other.

A square is a parallelogram that is both a rectangle and a rhombus.

What properties does a rectangle have?
Since a square is a parallelogram, opposite sides are congruent, opposite angles are congruent, consecutive angles are supplementary, and the diagonals bisect each other.
Since a square is a rhombus, each diagonal bisects a pair of opposite angles and each diagonal is the perpendicular bisector of the other.
Since a square is a rectangle, the diagonals are congruent.