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Question
A rope by which a cow is tethered is increased from 16 m to 23 m. How much additional ground does it have now graze?
Solution
r1 = 16 m
r2 = 23 m
Amount of additional ground available = Area of the bigger circle -- Area of the smaller circle
`= π (r_1^2 - r_2^2)`
= π (232 - 162)
= π (23 + 16)(23-26)
= 858 m2
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