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A tag is in the form of a hemisphere surmounted by a right circular cone of same base radius as that of the hemisphere. If the radius of the base of cone is 21cm and its volume is 2/3 of volume of hemisphere calculate height of cone and surface area of toy?

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Given radius of cone = radius of hemisphere

Radius (r) = 21cm

Given that volume of cone =2/3 Volume of hemisphere

l = √(h2 + r2)

l = √(282 + 212)

l = √(784 + 441)

l = √(1225)

l = 35cm

S1π(21)(35) cm2

S1 = 2310 cm2

Curved surface area off hemisphere = 2πr2

S2= 2 x π(21)2

S2 = 2772 cm2

Total surface area (S) = S1 +S2

= 2310 + 2772 = 5082 cm2

Curved surface area of toy = 5082 cm2

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