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Subject – Mathematics

Chapter 9 – AREA & PERIMETER

Sub-topic 2: PERIMETER OF SQUARE AND RECTANGLE:

Perimeter of a Square
A square is a type of rectangle in which the adjacent sides are equal. In other words,
all the sides of a square are equal.
Following are the properties of a square:
(i) All the angles in a square are the same and equal 90º.
(ii) All the sides of a square are equal.
Perimeter of a square
The perimeter of a square is the total length of all the sides of the square. Hence we
can find the perimeter of a square by adding all its four sides.

The perimeter of the given square is a + a + a + a. Since all sides of a square are
equal, we only need one side to find its perimeter.

The perimeter of the given square is:
a + a + a + a = 4 a units.
Hence, the formula of the perimeter of a square = 4 × (length of any one side).

Perimeter of a Rectangle
Rectangles are four-sided polygons. Following are the properties of a rectangle:

(i) All the angles of a rectangle are 90º.
(ii) Opposite sides of a rectangle are always the same in size.