Question

We have a garden that measures 17 feet by 20 feet. We want to pour concrete for a 3‐foot‐wide sidewalk around the garden. To make the forms for the concrete, we will need to buy some lumber. How many feet of lumber will we need just for the perimeter of the walk? (Consider both the inside and the outside perimeter.)

Answer 1

The inside perimeter would be the perimeter of the garden: 17 + 17 + 20 + 20 = 74 feet.

The outside dimensions would be 6 feet longer on each side ( 3 feet wide on both sides for the sidewalk)

Outside perimeter: 23 + 23 + 26 + 26 = 98 feet.

Total = 74 + 98 = 172 feet.