For a regular polygon with n sides and side length s, the perimeter P equals

• A. P = s
• B. P = n s
• C. P = n + s
• D. P = n^2 s

Answer: (B)

Perimeter is the total length around the figure, so you add up the lengths of all the sides. In a regular polygon, every side has the same length, call it s, and there are n sides. So you’re adding s together n times, which gives P = n × s. That’s why the correct expression is P = n s.

For a quick check, if you have four sides each of length 3, the perimeter is 3 + 3 + 3 + 3 = 12, which is 4 × 3. The other options don’t reflect adding all the sides: just s would be one side, n + s would mix a count with a length, and n^2 s would overcount beyond the simple sum of all sides.