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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
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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