What Does Perimeter Mean?

• Perimeter is the distance around the outside of a shape.
• It is measured as a length and can be in a range of units such as cm, inches, feet, miles, etc.

In the triangle below, the word 'perimeter' has been written around the outside going all the way round the triangle to show what the perimeter represents visually.

One way I like to imagine perimeter is if you dropped a tiny stick-person on the outside of a shape.

The stick-person walks all the way around the outside of the shape until they got back to where they started.

The distance the person walked would be the perimeter of the shape.

To find the perimeter of a shape you basically just need to add up the length of each of the sides.

If the shape is drawn accurately to scale, you can simply use a ruler and measure the length of each side and then add up all the lengths to find the perimeter.

However you will often be required, particularly at a higher level, to use geomtric properties of shapes and formulas to work out some of the missing lengths of shapes which are not drawn to scale.

To help you further understand what does perimeter mean, we have looked at working out the perimeter of some 2d shapes below.

How to find the perimeter of a rectangle.

• To find the perimeter of any shape we just need to add up the length of each side.
• In any rectangle, however, opposite sides are always equal in length.
• The perimeter of a rectangle can be found by adding the length of the 2 adjacent sides together and doubling the answer.
• Or Perimeter of a rectangle = (length + width) x 2
• Another way to find the perimeter quickly is to double the length of each of the adjacent sides and add them together.
• Perimeter = (length x 2) + (width x 2).

A rectilinear shape is a closed shape made up of just vertical and horizontal lines.

• To find the perimeter, we simply need to add up the lengths of the sides.
• If the length of the sides are not given, we will need to measure them first.
• If the shape is not drawn to scale and several lengths are missing, we will need to use our logical thinking and calculation skills to find the missing lengths.

How do we find the perimeter of regular shapes?

Well, a regular shape is a polygon that has all sides and angles equal.

When we are looking at perimeter, it is the 'all sides equal' part that we are interested in.

• To find the perimeter of a regular shape, we simply need to multiply the length of one side by the number of sides.

The perimeter worksheets are all graded in order from easiest to hardest.

Using these sheets will help your child to:

• work out the perimeter of a range of rectangles;
• find the perimeter of rectilinear shapes.

All the sheets in this section support Elementary Math Benchmarks.

This hub page contains links to all of our Area Worksheets.

Using these sheets will help your child to:

• work out the areas of a range of rectangles and rectilinear shapes;
• find the area of right triangles and quadrilaterals.

Here is our selection of measurement worksheets for 3rd graders.

These sheets involve reading scales going up in halves, ones, fives, tens, fifties and hundreds to find the length, weight or liquid capacity.

Using these sheets will help children to consolidate their counting and place value as well as learning to read and estimate using a simple scale.

Another way to learn about 'What does perimeter mean' is through exploring shapes.

This online area and perimeter activity by toytheater.com will let you explore 'what does perimeter mean' through creating your own shapes.

The link below will open in a new browser window.

The Math Salamanders hope you enjoy using these free printable Math worksheets and all our other Math games and resources.

We welcome any comments about our site or worksheets on the Facebook comments box at the bottom of every page.