Worksheet · Grades 3–4 · Geometry
Perimeter Worksheet
Two A4 pages: perimeter of rectangles, squares, triangles and an L shape, working backwards to a missing side and an answer key.
Perimeter
1 Once around the outside.
Count the centimeters on all four sides and add them.
+ + + = cm2 Perimeter of rectangles (in cm).
a) 7 cm long, 4 cm wide
b) 12 cm long, 8 cm wide
c) 10 cm long, 6 cm wide
3 Square and triangle.
a) A square has sides of 4 cm. Perimeter in cm?
b) A triangle has sides of 8 cm, 6 cm and 5 cm. Perimeter in cm?
4 The L shape.
Add all six sides. How many cm is it?
5 Think backwards.
a) A rectangle has a perimeter of 26 cm and is 8 cm long. How wide is it (in cm)?
b) A square has a perimeter of 28 cm. How long is one side (in cm)?
★ Brain teaser
A rectangle has a perimeter of 18 cm and is twice as long as it is wide. How long and how wide is it?
6 Draw two different rectangles with a perimeter of 14 cm. Length and width always add up to 7 cm.
Perimeter
1 Once around the outside.
2 Perimeter of rectangles (in cm).
3 Square and triangle.
4 The L shape.
Shortcut: the perimeter is the same as for the whole rectangle, 2 × 6 + 2 × 6.
5 Think backwards.
★ Brain teaser
6 Draw two different rectangles with a perimeter of 14 cm.
What is on the worksheet?
The example at the top adds the four sides of a rectangle. In task 1 your child counts the centimeters along each side of a shape on the grid. Task 2 works out the perimeter of rectangles from length and width, and task 3 does the same for a square and a triangle. Task 4 adds the six sides of an L shape, and task 5 works backwards from the perimeter to a missing side. A brain teaser and a grid for drawing two different rectangles with the same perimeter finish page 1. Page 2 has all the answers.
Who is it for?
Grades 3 and 4, alongside area: perimeter is the distance around a shape, area the space inside.
How to use it
Trace the outline with a finger or a colored pencil first. That shows clearly which lengths belong to the perimeter.
Frequently asked questions
Is there an answer key?
Yes. Page 2 shows every answer and a short note for parents and teachers. You can leave it out when you print.
Can I get new problems?
Yes. “New numbers” opens the worksheet generator with the same topic and new numbers, as often as you like.
What is the difference between area and perimeter?
Perimeter is the length around the outside, measured in centimeters. Area is the space inside, measured in square centimeters.