This resource has been contributed by Winpossible, and can also be accessed on their website by clicking here - Perimeter of a Polygon
In this section; with the help of some examples and solution, we'll explore how to calculate the perimeter of the polygons. The perimeter is one dimensional and measured in linear units such as feet, meters or similar units. To find the perimeter of a polygon, follow these simple steps:
- Measure the length of each side of the shape using the same unit of measurement.
- Add all the lengths of each side together.
- Write the answer using the same unit of measurement or an equivalent unit of measurement.
For example, if 'P
' is the perimeter, 'S
' is the length of each side and 'n
' stands for the number of sides of the polygon:
The perimeter of a pentagon ABCDE
with each side measuring 3cm, is 15cm. The perimeter of a rectangle is the distance around the outside of the rectangle. It has four sides and opposite sides are congruent. If the length of a rectangle is l
and the width is w
, then the perimeter can be calculated by
E.g., to calculate the perimeter of the rectangle ABCD
, having length CD
= 9 cm and width BC
= 4 cm, substitute 9 for l
and 4 for w
in above expression. It comes to P
= 2(9 + 4), and that gives 26cm.
similarly, if a is the measure of the side of a square, then perimeter is given by
for example, if each side of a square is 10 cm, then the perimeter is P
= 4 × 10, which works out to 40cm.
This FREE mini-lesson is a part of Winpossible's online course that covers all topics within Geometry. Click on the video below to go through it. If you like it, you can buy our online course in Geometry by clicking here.