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Question
A circular path has to be constructed around a circular ground. If the areas of the outer and inner circles are 1386 m2 and 616 m2 respectively, find the width and area of the path
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Solution
Area of the outer circle = 1386 m2
πR2 = 1386 m2
Area of the inner circle = 616 m2
πr2 = 616 m2
Area of the path = Area of outer circle – Area of the inner circle
1386 m2 – 616 m2
Area of the path = 770 m2
Also πR2 = 1386
R2 = `(1386 xx 7)/22`
R2 = 63 × 7
R2 = 9 × 7 × 7
R2 = 9 × 49
R2 = 32 × 72
R = 3 × 7
Outer Radius R = 21 m
Again πr2 = 616
`22/7 xx "r"^2` = 616
r2 = 28 × 7
r2 = 4 × 7 × 7
r2 = 4 × 49
r2 = 22 × 72
r = 2 × 7
Inner radius r = 14 m
Width of the path = Outer radius – Inner radius
= 21 – 14
Width of the path = 7 m
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