7. Area of rectangle=
lxb
We have, length of rectangle (l) =∏r
Breadth of rectangle (b) = r
So that, area of the rectangle (A) = l x b
= ∏r x r
= ∏r2
This rectangle is made by a circle.
So, the area of rectangle is equal to the area of the circle.
Hence,
Area of the circle is ∏r2.1/22/2020 7memadhav7@gmail.com
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Class work
1) Find the area of the circle having radius 5 cm where ∏ = 22/7.
2) A circular ground has 700 m diameter then calculate its area.
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Solution for first question:
1) Find the area of the circle having radius 5 cm where ∏ = 22/7.
Solution:
Given, radius of circle = 5 cm and ∏ = 22/7
We know, Area of circle = ∏ r2
= 22/7 X 52
= 22X25/7
= 78.57 cm2 Ans.
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Solution for second question:
2) A circular ground has 700 m diameter then calculate its area.
Solution:
Given, diameter of circular ground(d) = 700 m and ∏ = 22/7
radius (r) = 700/2 = 350 m
We know, Area of circle = ∏ r2
= 22/7 X3502
= 22X122500/7
= 385000 m2 Ans.
