Perimeter of a square
The perimeter of a square equals four times its side length: P = 4s. Since all four sides of a square are equal, measuring one side and multiplying by 4 gives the total boundary distance. In Grade 6 Saxon Math Course 1 (Chapter 1: Number, Operations, and Algebra), students apply this formula and its inverse: s = P ÷ 4, used when the perimeter is known and the side length must be found. For example, a square garden fence measuring 36 meters total has each side = 36 ÷ 4 = 9 meters. Students distinguish perimeter (linear units) from area (square units).
Key Concepts
Property Since a square has four sides of equal length, its perimeter $P$ is four times the side length $s$, so $P = 4s$. To find the side length from the perimeter, you can calculate $s = P \div 4$.
Examples A square with 12 inch sides has a perimeter of $4 \times 12 \text{ inches} = 48 \text{ inches}$. If a square's perimeter is 20 cm, the length of each side is $20 \text{ cm} \div 4 = 5 \text{ cm}$. A square field with a perimeter of 400 meters has sides that are each $400 \text{ m} \div 4 = 100 \text{ m}$ long.
Explanation A square is a super special shape where all sides are best friends and insist on being the exact same length! So, instead of adding the same number four times, you can just use a quick multiplication shortcut. Finding the length of a side from the perimeter is just doing that same cool trick in reverse. Teamwork for numbers!
Common Questions
What is the formula for the perimeter of a square?
P = 4s, where s is the length of one side. Since all four sides are equal, multiply the side length by 4.
If a square has a side length of 11 cm, what is its perimeter?
P = 4 × 11 = 44 cm.
How do you find the side length of a square if you know its perimeter?
Divide the perimeter by 4: s = P ÷ 4. For P = 52 m, each side = 52 ÷ 4 = 13 m.
What is the difference between perimeter and area of a square?
Perimeter measures the total boundary length in linear units (cm, m). Area measures the flat space inside in square units (cm², m²). For a square: P = 4s and A = s².
A square has a perimeter of 28 feet. What is its side length?
s = 28 ÷ 4 = 7 feet.