 # Geometry: Perimeter of Polygons

Related Topics:
More Lessons on Geometry

In these lessons, we will learn the perimeter of the following polygons:
• square
• rectangle
• parallelogram
• triangle
• rhombus
• trapezoid
We will also learn how to solve word problems involving perimeter of polygons.

### Perimeter of Polygons

The perimeter of a polygon is the sum of the lengths of its sides. It is the distance around the outside of the polygon.

### Perimeter of a Square

Since the sides of a square are equal, the perimeter of a square is 4 times the length of its side. Perimeter of a square = s + s + s + s = 4s

where s is the length of one side

### Perimeter of a Rectangle

A rectangle has four sides, with opposite sides being equal in length. Perimeter of a rectangle = l + l + w + w = 2(l + w),

where l is the length and w is the width of the rectangle.

Worksheet 1, Worksheet 2, Worksheet 3 to calculate the area and perimeter of rectangles.

### Perimeter of a Parallelogram

Similar to a rectangle, a parallelogram has four sides with opposite sides being equal in length. Perimeter of a parallelogram = l + l + w + w = 2(l + w)

where l is the length and w is the width of the parallelogram.

Worksheet to calculate the area and perimeter of parallelograms

### Perimeter of a Triangle Perimeter of a triangle = a + b + c

where a, b and c are the lengths of each side of the triangle.

### Perimeter of a Rhombus

A rhombus has 4 equal sides, so the perimeter of a rhombus is 4 times the length of its side. Perimeter of a rhombus = s + s + s + s = 4s

where s is the length of one side

### Perimeter of a Trapezoid a is parallel to b

Perimeter of a trapezoid = a + b + c + d

where a, b, c and d are the lengths of each side.

### Videos

How to find the Perimeter of a Rectangle? How to find the Perimeter of a Parallelogram? How to find the Perimeter of a Trapezoid? How to find the perimeters of rectangles, squares, triangles and other polygons?

### Word Problems involving perimeter of polygons

Example:
A rectangle is three times as long as it is wide. If the perimeter is 62 cm, what is the length?
The width of a rectangle is 6 cm less than the length. If the perimeter is 52 cm, what is the width? Example:
The length of a rectangle is 7 cm more than 4 times its width. It perimeter is 124 cm. Find its dimensions. Example:
The width of a rectangle is 4 ft smaller than 3 times its length. Its perimeter is 144 ft. Find its dimensions.

Example:
A rectangle garden is 2.5 times as long as it is wide. It has a perimeter of 1.6 feet. How long and wide is the garden? Example:
The perimeter of a triangle is 26 cm. The first side is 6 cm shorter than the second side. The third side is 2 cm shorter than twice the length of the first side. What is the length of each side?

Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations. 