# Rectangle

## Perimeter, Area, Diagonal of rectangle

The best calculator to calculate the rectangle you’ve ever seen

### Calculation

Enter values into the two yellow fields - the rest will be calculated automatically.

If you change a value in the field, all the marked ones recalculate accordingly.

Using the checkbox you can choose **any three fields**,

that you want to calculate.

For decimals you can enter either **points** or **commas**.

The result will be in the units that you enter into the fields.

For example, if you enter decimeters, the result will also be in decimeters.

If a **NaN** error occurs,

you have probably entered invalid values.

### Formula

O = |
2 × (a + b) | [m] | |

P = |
a × b | [m²] | |

u = |
√a² + b² | [m] | |

tg α = |
b / a | [º] | |

+ reverse formulas www.wikina.org/a/Rectangle |

**a** … side a length

**b** … side b length

**u** … diagonal

**α** … angle

### Rectangle and circle

**Diagonal** (u) = diameter of a circle circumscribing a rectangle

**shorter side of the rectangle** (a) = diameter of a circle inscribing a rectangle

Other formulas are also avaiable on Wikina under the Rectangle keyword.

### Online rectangle calculation

Calculator for calculating rectangle's surface, converting the perimeter of a rectangle, rectangle formulas. Calculation of a diameter of a circle circumscribing or inscribing a rectangle, calculation of surface from perimeter. Calculation of rectangle's perimeter online. Rectangle formulas.

### Links

### How to calculate ...

Bold shapes and objects are already in operation. The others contain only a formula.

**Circle**- online calculator**Square**- online calculator**Cube**- online calculator**Sphere**- online calculator**Cylinder**- online calculator- Triangle
- Cuboid
- Ellipse

**GEOMETRY**- disambiguation

### You might be interested

- Mathematics:

Angle - Physics:

Wavelength - Financement:

VAT Calculator