What is the perimeter of a square with side length s?

• A. s^2
• B. 2s
• C. 8s
• D. 4s

Answer: (D)

The idea being tested is that a square’s boundary length comes from its four equal sides. Each side has length s, so walking around the square you cover s on four sides: s + s + s + s, which simplifies to 4s. This matches the standard formula for a square’s perimeter: P = 4s.

Why these other expressions don’t fit: s^2 represents area, not the boundary length. Two times s only accounts for two sides, not the full loop. Eight times s would count eight side-lengths, which isn’t appropriate for a four-sided figure.

So the perimeter is four times the side length: 4s.