Perimeter of a square
The perimeter of a square is the total length of all four sides. Since all sides of a square are equal, the formula is P = 4s, where s is the side length. A square with 9 cm sides has a perimeter of 4 x 9 = 36 cm. This 7th grade geometry skill from Saxon Math Course 2 is the simplest application of the regular polygon perimeter formula and appears in fencing, framing, and border problems across math and science.
Key Concepts
Property The perimeter of a square is the total distance around its four equal sides. The formula is $P = 4s$, where $P$ is the perimeter and $s$ is the length of one side of the square.
Examples A square garden with sides of 24 feet needs: $P = 4 \times 24 \text{ feet} = 96$ feet of border. A square photo frame with 10 inch sides has a perimeter of: $P = 4 \times 10 \text{ inches} = 40$ inches. A square park with a side length of 100 meters has a perimeter of $P = 4 \times 100 = 400$ meters.
Explanation Think of putting a fence around a square yard. You need to know the total length for all four sides. Since all sides of a square are equal, you can just measure one side and multiply it by four. It’s a simple shortcut to avoid adding the same number four times!
Common Questions
What is the formula for the perimeter of a square?
Perimeter = 4 x side length, written P = 4s. All four sides of a square are equal, so multiplying one side by 4 gives the total perimeter.
How do you find the side length from the perimeter of a square?
Divide the perimeter by 4. If P = 36 cm, then s = 36 / 4 = 9 cm.
How is the perimeter of a square different from a rectangle?
A square has four equal sides so P = 4s. A rectangle has two pairs of equal sides so P = 2l + 2w. If all sides of a rectangle are equal, it is a square and both formulas give the same result.
What grade learns the perimeter of a square?
Perimeter of a square is foundational geometry covered in Saxon Math Course 2 for Grade 7, connecting to broader work on regular polygons and area.
How is perimeter of a square used in real life?
Perimeter of a square determines how much fencing encloses a square yard, how much trim borders a square window, or how long a path around a square park is.
What is the difference between perimeter and area of a square?
Perimeter is the total length around the outside (P = 4s). Area is the space inside the square (A = s squared). They use the same side length but measure entirely different things.