How do I work out perimeter?
The perimeter is everything around the shape and consists of adding each of the lengths around the shape together. Unless stated, you can assume if one side of a rectangle has been labelled as a size, the opposing side is the same length.
Example 1:
Step 1: Identify the lengths of the rectangle. Looking straight on at the rectangle, we can see that the top is equal to 6 cm and therefore (as it has not been stated otherwise) the opposite length (the bottom) must also be 6 cm. We can also see that the length on the right of the rectangle is 2 cm and therefore, the opposing side must also be 2 cm.
Step 2: Add together the lengths from all sides. 6 + 2 + 6 + 2 = 16 cm. As it is perimeter, it is 'cm', only if it is area it is 'cm²'. The video to the right explains how to work out the perimeter of the shape above. |
Example 2: