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SAI International School
Grade -VI

Mathematics

Chapter – 10 – MENSURATION

Lesson Note – 10.1

Subtopics:
 Introduction
 Perimeter

Introduction
 Plane Figures
 The closed 2-D shapes are referred to as plane figures.

Here “C” is the boundary of the above figure and the area inside the boundary is the region of this
figure. Point D comes in the area of the given figure.
 Perimeter

 If we go around the figure along its boundary to form a closed figure then the distance covered is
the perimeter of that figure.
 Perimeter refers to the length of the boundary of a closed figure.
 If a figure is made up of line segments only then we can find its perimeter by adding the length of
all the sides of the given figure.
Example:
Find the Perimeter of the given figure.

Solution:
Perimeter = Sum of all the sides
= (12 + 3 + 7 + 6 + 10 + 3 + 15 + 12) m = 68 m