# Perimeter Worksheet

Document Sample

```					Perimeter of Polygons

By Sara Gregurash
Perimeter
• Perimeter is the distance (length) around the outside of a
polygon. To find the perimeter of a polygon, take the sum of
the distance along each of its sides (P = sum of all the sides).
It is important to study perimeter because it makes everyday
life easier.

• For example, the perimeter was needed for a fence that was
placed around a backyard. The amount of fence needed to
enclose the yard had to be figured out, which is the perimeter.
You have to know how much fence you need in order to buy
the fence (a length in feet, yards, or meters) at a store.

• This presentation will show you how to figure out the
perimeter of polygons. I have used smaller units like
centimeters and inches because these polygons are smaller
than a fence.
Perimeter of a triangle
• To find the perimeter of a triangle you have to add up the three
sides. The equation looks like this:
P=s+s+s

• Using the triangle below, the sides have a length of 8
centimeters, 6 centimeters, and 5 centimeters.
P=s+s+s
P = 8 cm + 6 cm + 5 cm
P = 19 cm
8 cm
5 cm

6 cm
Perimeter of a square
• The equation to find the perimeter of a square is P = s +
s+s+s

• For the square below the length of each side is 4 inches.
P=s+s+s+s
P = 4 in + 4 in + 4 in + 4 in
P = 16 in

4 in
Perimeter of a rectangle
• To find the perimeter of a rectangle you have to use the
formula, P = 2l + 2w ( l is the length and w is the width).

• The length of the rectangle below is 9 inches and the width is
5 inches.
P = 2l + 2w
P = 2(9 in) + 2(5 in)
P = 18 in + 10 in
P = 28 in
5 in

9 in
Perimeter of a parallelogram
• To find the perimeter of a parallelogram, you have to use the
following equation:
P = 2l + 2w

• Using the parallelogram below, the length is 20 centimeters
and the width is 7 centimeters.
P = 2l + 2w
P = 2(20 cm) + 2(7 cm)
P = 40 cm + 14 cm
P = 54 cm
7 cm

20 cm
Perimeter of regular polygons
•   Regular polygons have all sides that are equal length and all
angles are equal.
•   A square and an equilateral triangle are examples of regular
polygons. Another way to find the perimeter of a regular polygon is
to multiply the number of sides by the distance along one side.
•   Here is an example of a regular polygon called a hexagon (6 sided
figure). The equation to find the perimeter of a hexagon is:
P = 6 · length of a side
•   The perimeter of the hexagon below with sides that have a length of 4
inches is:
P = 6 · length of a side
P = 6 · 4 in                                       4 in
P = 24 in
Websites
• Here are links to lessons, exercises, and
worksheets about area and perimeter of
polygons. You can practice your skills
from these sites.

Perimeter Lesson and Exercise
Exercise on Area and Perimeter
Area and Perimeter Worksheet
Have fun with perimeter
• These two websites have fun activities to do
that are related to polygon shapes and the
area and perimeter of polygons.

Polygon Crossword

Polygon Word Search
• Now, that you are familiar with
calculating the perimeter of polygons it’s
time for my worksheet. This will allow
you to see how well you learned the
material. Good luck!

• Here are the answers to my worksheet.
Test Time
• This is your chance to see how much you
have learned from all three of my power
point presentations.