Sub. :- Mathematics

Perimeter

Std. :- 5th

Chapter no. 20

A perimeter is a path that surrounds an area. The word comes from the Greek peri (around) and meter (measure). The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called its circumference.

In short Perimeter of a figure is the sum of the lengts of all sides of that figure

Perimeter of a Rectangle :- Formula

3 cm

1.5 cm

P

Q

S

R

The Perimeter of a rectangle PQRS = Sum of lengts of all sides

=3+1.5+3+1.5

= 3+3+1.5+1.5

=2 X length + 2 X breadth

The Perimeter of a rectangle = 2 X length + 2 X breadth

Note :- If length & breadth of a rectangle are in Centimeters then unit of perimeter of a rectangle is cmIf length & breadth of a rectangle are in Meters then unit of perimeter of a rectangle is m

The length of a rectangular playground is 120 m and its breadth is 75 m. Find its perimeter.

Length of a rectangular playground = 120 m

breadth of a rectangular playground =75 m

The Perimeter of a rectangular playground = 2 X length + 2 X breadth

= 2 X 120+ 2 X 75

= 240 +150

= 390

The Perimeter of the rectangular playground is 390 m.