Part Two
Lesson 12 – Perimeter and Area
Exercise
1. Find the perimeter of the figures given below.
(1)
Ans:
Perimeter = 4 + 1 + 4 + 1
∴ Perimeter = 10 cm
(2)
Ans:
Perimeter = 3 + 3 + 3 + 3
∴ Perimeter = 12 cm
(3)
Ans:
Perimeter = 3 + 4 + 5
∴ Perimeter = 12 cm
(4)
Ans:
Perimeter = 2 + 7 + 2 + 7
∴ Perimeter = 18 cm
(5)
Ans:
Perimeter = 3 + 4 + 3 + 4
∴ Perimeter = 14 cm
2. The sides of a rectangular field are 150m, 120m, 150m and 120m. Find the perimeter of the field.
Ans:
Perimeter of the field = 150 + 120 + 150 + 120
∴ Perimeter of the field = 540 cm
Perimeter of the rectangular field is 540 cm
Exercise
Find the area of the following figures (all small squares are of 1 sq cm area).
(1)
Ans:
Area of identity card = number of squares
∴ Area of identity card = 6 + 6 + 6 + 6
∴ Area of identity card = 24 sq. cm
(2)
Ans:
Area of shape = number of squares
∴ Area of shape = 2 + 2
∴ Area of shape = 8 sq. cm
(3)
Ans:
Area of shape = number of squares
∴ Area of shape = 4 + 4 + 4 + 4
∴ Area of shape = 16 sq. cm
(4)
Ans:
Area of shape = number of squares
∴ Area of identity card = 7 sq. cm