# Rectangle Calculator

Use our rectangle calculator to find the area, perimeter, and diagonals of your shape.

Enter any two properties of a rectaingle to calculate the remaining properties.

## Solution:

 Length (l): 3 Width (w): 4 Area (A): 12 Perimeter (P): 14 Diagonal (d): 5 Circumradius (R): 2.5 Inradius (r): 1.5
Learn how we calculated this below

## How to Calculate the Properties of a Rectangle

A rectangle is a four-sided polygon (quadrilateral) with opposite sides that are equal in length and four right angles. Due to its symmetry, a rectangle has properties that distinguish it from other quadrilaterals, such as the parallelogram or the trapezoid.

A rectangle is defined by the length of its length and width, but also has other properties such as its area, perimeter, length of its diagonal bisection, circumradius, and inradius.

### How to Calculate the Area of a Rectangle

The area of a rectangle is given by the product of its length and width. Thus, the formula to calculate a rectangle area is:

A = l \times w

The area A is equal to the length l multiplied by the width w.

### How to Calculate the Perimeter of a Rectangle

The perimeter of a rectangle is the sum of all its sides. Given its symmetrical nature, the perimeter can be expressed as:

P = 2l + 2w

The perimeter P is equal to twice the length l plus twice the width w.

### How to Calculate the Diagonals of a Rectangle

When you draw a diagonal across a rectangle, you effectively divide the rectangle into two congruent right triangles. The diagonal forms the hypotenuse of these triangles, and the rectangle’s length and width form the remaining two sides of the triangle.

Because the diagonal forms a right triangle, you can use the Pythagorean theorem to calculate the length of the diagonal. The Pythagorean theorem states:

a^{2} + b^{2} = c^{2}

The formula to calculate the length of a diagonal that bisects a rectangle is:

l^{2} + w^{2} = d^{2}

This can be simplified to:

d = \sqrt{l^{2} + w^{2}}

The diagonal d of a rectangle is equal to the square root of the length l squared plus the width w squared.