Page 107 - Revised Maths Wisdom Class - 6

7 Perimeter and Area

CHAPTER OUTLINES

● Introduction ● Perimeter of a Triangle ● Area of Irregular Shapes
● Perimeter ● Perimeter of Regular Shape ● Area of Regular Shapes
● Perimeter of a Rectangle ● Area ● Finding Area by using a Squared Paper

RECALL

● The sum of the lengths of the line segments, enclosing a polygon is called its perimeter.
● The perimeter of a figure is expressed in units such as mm, cm, m ..... etc.
● Perimeter can be found only for the closed figures.
● Region enclosed by a closed figure is called its area.
● The area of figure is expressed in square units such as mm , cm , m ..... etc.
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Introduction
Perimeter and Area of closed figures or polygons i.e., 2D figures are studied under the branch of Mathematics
called mensuration. As we know that line segment is one dimensional (1D) and has only length. When these line
segments are joined to form a closed figure, it becomes two dimensional as shown here:

D Length C

Breadth Breadth

A B
Length
Perimeter

The perimeter of any closed figure is the length of its boundary. For example, the perimeter of the following figure
is:
3 m
2 m 5 m

6 m 4 m
7 m

3 m + 5 m + 4 m + 7 m + 6 m + 2 m = 27 m