If an area to be fenced measures 30 feet on each of the four sides, what is the total length of fencing required?

• A. 90 ft
• B. 120 ft
• C. 200 ft
• D. 300 ft

Answer: (B)

Fencing around a shape uses its perimeter—the total distance around the outside. For a square, all four sides are the same length, so you add the side length four times. If each side is 30 feet, the total fencing needed is 4 × 30 = 120 feet. This accounts for all four sides of the square. The other numbers would correspond to fewer than four sides or a mismatch with four equal sides, so they don’t fit this scenario. The correct fencing length is 120 feet.