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A sector with radius r and length of its...

A sector with radius r and length of its are I is cut from a circular sheet of paper. Fold it as a cone. How can you derive the formula of its curved Surface area `A = pi r l`

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VGS PUBLICATION-BRILLIANT-SURFACE AREAS AND VOLUMES-EXERCISE
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  5. Find the slant height and vertical height of a Cone with radius 5.6 cm...

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  14. From a circle of radius 15cm . A sector with angle 216 ^(@) is cut ou...

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  15. The height of a tent is 9m. Its base diameter is 24m. What is its slan...

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  16. The curved surface area of a cone is 1159( 5)/( 7) cm ^(2) .Area of ...

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