Question

13 From a rectangular piece of metal sheet of length and breadth 1.60 m and 80 cm respectively, 3 circular
sheets of 20 cm radius are cut out. What area of metal is left? Use t = 3.14.​

Answer 1

Explanation:

Length of rectangular sheet = 1.60 m = 160cm

Breadth of rectangular sheet = 80 cm

Area of rectangular sheet = l X b = 160 X 80 = 12800 cm2.

Radius of 1 circular sheet = 20cm

Area of 1 circular sheet = πr2 = 3.14 X 20 X 20 = 3.14 X 40 = 125.6 cm2.Area of 1 Area of 3 circular sheets = 125.6 X 3 = 376.8 cm2.

Area of rectangular sheet left = Area of rectangular sheet - area of 3 circular sheets

= 12800 - 376.8 cm2 = 12432.2 cm2

So, 12432 cm2 of the rectangular metal sheet is left.