Question

please tell me the answer of this question

Answer 1

Let the common ratio be x.

Given that Radius of the cone  = 5x.

Given that Height of the cone = 12x.

Given volume of cone = 314cm^3.

We know that volume of cone = 1/3pir^2h

  314 = 1/3 * 3.14 * (25x)^2 * 12x

 314 = 314x^3

x^3 = 1

x = 1.

Hence Radius r = 5 * 1

                           = 5cm.

Height = 12 * 1

             = 12cm.


Now,

We know that slant height l^2 = r^2 + h^2

                                                   = 25 + 144

                                                   = 169

                                          l = 13cm.



Therefore the slant height = 13cm.


Now,

Curved surface area = pi * r * l

                                   = 22/7 * 5 * 13

                                   = 204.2cm^3.


Therefore the C.S.A of the cone = 204.2cm^2.


Hope this helps!

Answer 2

Hope it is helpful for you☺