# Rectangles Discovery Activity

- Author:
- Paul Kirila

- Topic:
- Rectangle

## Definition of a rectangle

A

__is an equiangular parallelogram.__**rectangle**What is the measure of each angle in a rectangle?

__Since a rectangle is a parallelogram, it has all of the properties of a parallelogram:__

- opposite sides are parallel
- opposite sides are congruent
- opposite angles are congruent
- consecutive interior angles are supplementary
- diagonals bisect each other

**There is one additional property of a rectangle that involves the diagonals.**

## Make a conjecture about the diagonals of a rectangle. Test your conjecture by moving around points A, B, and C in rectangle ABDC below.

Type your conjecture here.

## What could we do to decide whether quadrilateral ABCD is a parallelogram? a rectangle?

How would you show whether quadrilateral ABCD above is a parallelogram?

How would you show whether quadrilateral ABCD above is a rectangle?