Perimeter Resources

Perimeter is another geometric concept that your child will begin learning in third grade. Perimeter is defined as the distance around a two-dimensional shape. Calculating perimeter requires addition and multiplication skills, so after your student has mastered those concepts, you can help them move on to our worksheet resources for perimeter.

Perimeter is the total length around a shape, and for different shapes, there are different ways to calculate it.

• Square: perimeter = 4 × s, where s is the length of a side
• Rectangle: perimeter = 2 × (w + h), where w is width and h is height
• Triangle: perimeter = a + b + c, where a, b, and c are the lengths of three different sides
• Circle: the perimeter for a circle is actually called the circumference. Circumference = 2 × π × r, where r is the radius.
• Quadrilateral: perimeter = a + b + c + d, where a, b, c, and d are lengths of different sides

If you want to learn more about the different shapes, you can check out our geometry page to get a better idea of what circles are and the different polygons you can calculate the perimeter of.

After you practice your perimeter skills with the resources on this page, you can then move over to our area resources to learn how to calculate the amount of space inside a shape.