Page 158 - Maths Class 04

11 Perimeter and Area

Perimeter

The word Peri is a Greek word which means around and meter means

measure. Therefore, perimeter means measuring around a figure or a curve.

The perimeter of a shape is the sum of all its sides.

Example : Find the perimeters of the given shapes.

a. 5 cm b. 6 cm c.
5 cm

4 cm 4 cm 3 cm
5 cm 5 cm

6 cm 4 cm
5 cm
20
20
12
Perimeter = cm Perimeter = cm Perimeter = cm
Example : Use a ruler and find the perimeter of this scenery.

8
Perimeter = _______ cm + 8 cm +
3
3
_______ cm + _______ cm.
= 22 cm

Perimeter of Geometrical Shapes

Perimeter of a Triangle
A
A triangle has three sides.

Perimeter = Sum of all its sides. 6 cm 2 cm

= AB + BC + CA
B C
= 6 cm + 8 cm + 2 cm 8 cm

= 16 cm

Mathematics-4 158