how do you find the width of a rectangle

Rectangle Shape

Rectangle Diagram with l = length and w = width
a = length side a
b = length side b
p = q = diagonals
P = perimeter
A = expanse
√ = square root

Computer Use

Use this reckoner if you know 2 values for the rectangle, including 1 side length, forth with surface area, perimeter or diagonals and you can summate the other 3 rectangle variables. A square calculator is a special case of the rectangle where the lengths of a and b are equal.

Units: Note that units of length are shown for convenience. They practise not affect the calculations. The units are in place to give an indication of the society of the calculated results such as ft, ftⁱⁱ or ft³. Any other base unit can be substituted.

Rectangle Formulas

Expanse of a rectangle:

A = ab

Perimeter of a rectangle:

P = 2a + 2b

Polygon diagonals of a rectangle:

p = q = √(a^two + bⁱⁱ)

Rectangle Calculations

Calculate A, P, p | Given a, b
Given sides lengths a and b summate area, perimeter and diagonals
- A = ab
- P = 2a + 2b
- p = q = √(a² + b²)
Calculate P, p, b | Given A, a
Given area and side length a calculate perimeter, diagonals and side b
- b = A / a
- P = 2a + 2b
- p = q = √(a² + b²)
Summate P, p, a | Given A, b
Given surface area and side length b calculate perimeter, diagonals and side a
- a = A / b
- P = 2a + 2b
- p = q = √(a^two + b²)
Calculate A, p, b | Given P, a
Given perimeter and side length a calculate area, diagonals and side b
- b = (P - 2a) / ii
- A = ab
- p = q = √(a² + b^two)
Summate A, p, a | Given P, b
Given perimeter and side length b calculate expanse, diagonals and side a
- a = (P - 2b) / 2
- A = ab
- p = q = √(a² + bⁱⁱ)
Summate A, P, b | Given p, a
Given diagonals and side length a summate area, perimeter and side b
- b = √(p^two - a²)
- A = ab
- P = 2a + 2b
Calculate A, P, a | Given p, b
Given diagonals and side length b calculate area, perimeter and side a
- a = √(p² - b²)
- A = ab
- P = 2a + 2b