Chapters

## What is a Perimeter

**perimeters,**let’s take a look at the definition below.

What is a perimeter? | A perimeter is the total length of the boundary of a figure. |

When do you use it? | When you have a two-dimensional shape |

Why do you use it? | It can be used in anything from construction to project planning. |

As you can see, perimeters can have many **applications.** Let’s take a look at the general formula for a perimeter.

Notation | Formula | |

Perimeter | Add up the length of all sides |

## Perimeter of Rectangle

In order to find the perimeter of a rectangle, you should understand what a rectangle is. Even when **rectangles** are different sizes, they all share the same properties. The table below has these properties as well as how to find the perimeter of any rectangle.

Property 1 | A polygon with four sides |

Property 2 | Opposite sides are parallel and congruent |

Property 3 | Has four right angles |

Perimeter |

The length and width of a rectangle correspond to the longest side and the **shortest side.**

## Perimeter of Square

In order to find the perimeter of a square, you should understand what a square is. Even when squares are **different sizes,** they all share the same properties. The table below has these properties as well as how to find the perimeter of any square.

Property 1 | A polygon with four sides |

Property 2 | Opposite sides are parallel, congruent and are all the same size |

Property 3 | Has four right angles |

Perimeter |

Because of **property** **2**, where all sides of a square are the same size, you can simply add the sides 4 times, which is the same as multiplying one side four times.

## Perimeter of Circle

In order to find the perimeter of a circle, you should **understand** what a **circle** is. Even when circles are different sizes, they all share the same properties. The table below has these properties as well as how to find the perimeter of any circle.

Property 1 | A set of points, or a line, that is shaped in an O |

Property 2 | All points, or points on the line, are equidistant from the centre |

Radius | The distance from the centre point to the outside of the circle |

Diameter | The distance from one end to another end of the circle through the centre |

Perimeter | Called the circumference |

Circumference |

## Perimeter of Equilateral Triangle

In order to find the perimeter of an **equilateral** triangle, you should understand what an equilateral triangle is. Even when equilateral triangles are different sizes, they all share the **same properties.** The table below has these properties as well as how to find the perimeter of any equilateral triangle.

Property 1 | A triangle, which has three lines and three interior angles |

Property 2 | All three angles are the same size, 60 degrees |

Property 3 | All sides are the same length |

Perimeter |

Because of property 3, we can multiply the **three sides** of the same length by 3 to get the perimeter.

## Perimeter of Isosceles Triangle

In order to find the perimeter of an **isosceles triangle,** you should understand what an isosceles triangle is. Even when isosceles triangles are different sizes, they all share the same properties. The table below has these properties as well as how to find the perimeter of any isosceles triangle.

Property 1 | A triangle, which has three lines and three interior angles |

Property 2 | Has two angles that are same size |

Property 3 | Has two sides are the same length |

Perimeter |

Because of property 3, we can multiply the 2 sides of the **same length** by 2 and add the length of the base(b) to get the perimeter.

## Perimeter of Scalene Triangle

In order to find the perimeter of a **scalene triangle,** you should understand what a scalene triangle is. Even when scalene triangles are different sizes, they all share the same properties. The table below has these properties as well as how to find the perimeter of any scalene triangle.

Property 1 | A triangle, which has three lines and three interior angles |

Property 2 | All three angles are a different size |

Property 3 | All three sides are a different size |

Perimeter |

Because of property 3, you need to add all sides to get the **perimeter.**

## Perimeter of Rhombus

In order to find the perimeter of a **rhombus,** you should understand what a rhombus is. The table below has these properties as well as how to find the perimeter of any rhombus.

Property 1 | A shape with four sides |

Property 2 | Opposite sides are parallel |

Property 3 | All four sides are congruent |

Perimeter |

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