Formula for the Perimeter of a Square
You will need to know how to calculate the perimeter of a square for your entrance exam.
The formula for the perimeter of a square is:
4 × L = P
In the formula above, L is the length of the side of the square and P is the perimeter of the square.
To understand exam questions on the perimeter of a square, you should know some facts about squares.
You should also understand the terminology relating to squares and other geometrical shapes.
You may want to have a look at our post on the area of a square after completing the exercises on this page.
Perimeter of a Square – Terminology
Quadrilateral:
A square is a type of quadrilateral.
“Quadrilateral” means that the shape has four sides.
Symmetry:
A square is said to have four lines of symmetry.
This means that a square has four sides, and all four sides are equal in length.
Rotational symmetry:
A square also has rotational symmetry.
This means that the square will look the same, regardless of how it is rotated.
So, you can turn a square on its side and it will look the same.
90° angles:
All angles in a square are 90 degrees.
Since all four angles are 90 degrees, a square is different than a polygon or hybrid shape.
Parallel lines:
A square has two pairs of parallel lines.
The left and right sides of the square will be parallel.
The top and bottom sides of the square will also be parallel.
Bisecting angles:
The diagonals in a square are equal.
The diagonals bisect, or cross each other, in the center of the square.
The diagonal lines form four right angles.
You will need to know these facts when working out other geometry problems on the exam.