If a rectangular fenced plot measures 30 feet by 40 feet, what is the total length of fencing required?

• A. 60 ft
• B. 100 ft
• C. 140 ft
• D. 180 ft

Answer: (C)

To fence around a rectangle, you need the perimeter—the distance all the way around. The perimeter equals twice the sum of the length and the width. With a length of 30 feet and a width of 40 feet, that’s 2 × (30 + 40) = 2 × 70 = 140 feet. So the total fencing required is 140 feet. The other numbers don’t work because they don’t account for all four sides: 60 covers only two short sides, 100 would miss portions of the sides, and 180 would require larger dimensions than given.