In geometry, a **rectangle** is defined as a quadrilateral where all four of its angles are right angles. A rectangle with vertices ABCD would be denoted as .

Rectangles hold the following properties:

- Opposite sides are of equal length (congruent)
- Adjacent sides meet at right angles
- All four angles are of equal measure (congruent)
- All four angles are right angles
- Adjacent angles are supplementary

- Opposite sides are parallel

- Diagonals are of equal measure (congruent)
- Diagonals bisect one another

## Area

The area of a rectangle is computed as the product of its length and its width:

## Perimeter

The perimeter of a rectangle is computed as:

## Circumcircle

The circumradius of a rectangle is:

## Incircle

The inradius of a rectangle is:

## Diangle length

The diangle length of a rectangle is: