A toy is in the form of a cone mounted on a hemisphere of radius 3.5 cm. The total height of the toy is 15.5 cm. Find the total surface area and volume of the toy.

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Sneha

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Saturday, 28 November 2020 08:35 AM

Total surface area of toy $=$ Curved surface area of cone $+$ surface area of hemisphere

Curved surface area of cone $=$ $prl$

Where $r=3.5cm$, Height $=15.5-3.5=12cm$

And hence, $l=12.5cm$ (by using formula $l_{2}=h_{2}+b_{2}$)

Therefore C.S.A. of cone $=p×3.5×12.5$

$=137.5cm_{2}$

Surface area of hemisphere $=2pr_{2}$

$=2×p×(3.5)_{2}$

$=77cm_{2}$

Hence T.S.A of toy $=77+137.5=214.5cm_{2}$