Question

Joe puts edging around a circular lawn with diameter 320 cm. The edging is sold in 180 cm lengths. How many lengths does he need?​

Answer 1

About 5.585 lengths

Explanation:

To find the length of edging needed, we need to use the formula for the circumference of a circle.

`C = 2\pi r`

`Radius = (1)/(2) diameter`

`r = (1)/(2) 320 = 160cm`

`C = 2\pi (160cm) = 1005.31cm`

Now to find the number of lengths needed, we divide the circumference by the circumference by the length of edging.

# of lengths = 1005.31 / 180 = 5.585