Page 189 - New Medley 4 Semester 2 PDF (Merged)

Mental
Test

Find the missing side of the following figures.
1. Perimeter = 20 cm 2. Perimeter = 130 cm 3. Perimeter = 11 m

?
? 3 m
7 cm
4 cm
20 cm 40 cm
1.5 m 2 m
? 2 m
30 cm

Finding Perimeter of a Rectilinear Figure on a Square Grid

To find the perimeter of a shape on a 1 2
square grid, count the number of unit 14 3
4 5 16
squares that touch the boundary.
13 A 6 15 1 2

14 3
12 7 B
Thus, perimeter of shape A = 14 units 13
11 10 9 8 12 4
10 11
And perimeter of shape B = 16 units
9 5
8 7 6
EXERCISE 8.1

A. Find the perimeter of each of the following figures.

20 cm 30 cm

1. 6 m 6 m 2. 20 cm 3. 30 cm 30 cm
10 cm

7 m 20 cm 30 cm
20 cm
3 km

4. 3 km 3 km 5. 50 cm 50 cm 6. 8 m 17 m

3 km 15 m
20 cm

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