A cone of height 24cm has a C.S.A 550m2 .Find its volume (pie =22/7)

Given height of the cone, h = 24 cm

Let r cm and l cm be the radius and slant height of the cone respectively.

Curved surface area of the cone = 550 cm(Given)

πrl = 550 cm2

https://s3mn.mnimgs.com/img/shared/discuss_editlive/1078112/2012_02_07_16_56_04/mathmlequation6685953999112987501.png

Squaring on both sides, we get

r (r + 576) = (175)= 30625

 r + 576 r – 30625 = 0

 r + 625 r – 49 r 2 – 30625 = 0

 r 2(r 2 + 625) – 49 (r 2 + 625) = 0

(r 2 + 625) (r 2 – 49) = 0

 r 2 – 49 = 0 (  r 2 + 625 ≠ 0)

 r 2 = 49

 r = 7 ( Radius cannot be negative)

Radius of the cone = 7 cm

Volume of the cone

https://s3mn.mnimgs.com/img/shared/discuss_editlive/1078112/2012_02_07_16_56_04/mathmlequation3752094147652774361.png

Thus, the volume of cone is 1232 cm3.

 

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