Final answer:
To estimate the number of 1 x 6s needed for the fence, we can assume the backyard is a rectangle and calculate the perimeter.
Step-by-step explanation:
To find out how many 1 x 6s are needed for the fence, we need to calculate the perimeter of the backyard. We know the length is 10 feet, but we don't have the width. However, if we assume that the backyard is a rectangle, we can use the formula for the perimeter of a rectangle: P = 2L + 2W. Since we only have one side length, we can't find the exact number of 1 x 6s needed, but we can estimate. If we assume the width of the backyard is 5 feet (half the length), then the perimeter would be 10 + 10 + 5 + 5 = 30 feet. So, we would need approximately 30 1 x 6s to enclose the backyard.