8.02 Perimeter of rectangles
Are you ready?
Do you remember how to find the perimeter of a shape?
Find the perimeter of the shape given.
Learn
A rectangle has two pairs of equal sides. Because of this, we can find the perimeter of a rectangle using a formula:
| Perimeter | $=$= | Length $+$+ Length $+$+ Width $+$+ Width |
| $=$= | $2$2$\times$× Length $+$+ $2$2$\times$× Width | |
| $=$= | $2$2$\times($×(Length $+$+ Width$)$) |
This video looks at using the properties of rectangles to calculate the perimeter. It also talks about some special notation that can be used to show when two sides have the same length.
Apply
Question 1
Find the perimeter of the rectangle shown.
Learn
A square has four sides of equal length. Because of this, we can find the perimeter of a square using the formula:
| Perimeter | $=$= | Length $+$+ Length $+$+ Length $+$+ Length |
| $=$= | $4$4$\times$× Length |
Apply
Question 2
Find the perimeter of the square shown.
Because a rectangle has $2$2 pairs of sides with equal length, we can add the length and width, then double it, to find the perimeter of a rectangle.
A square is a special kind of rectangle, with $4$4 sides the same length, so we can multiply its side length by $4$4 to find the perimeter.