Question

there are two cones the csa of one cone is twice that of the other. the slant height of the later is twice that of the former. find the ratio of their radii
plz give the ans it's urgent

Answer 1

Let radii of the cones be r1 ,r2 and slant height of the cones l1 and l2.

According to the question = πr1l1 = 2πr2l2

⇒ r1 l1 = 2r2 l2 -------(1)

Given that slant height of the second cone is twice the first cone i.e

 ⇒ l2 = 2 l1 ----------(2)

From (1) and (2) we get

 r1 l1 = 2r2 2l1

⇒ r1 = 4r2 

⇒ r1 / r2  = 4 / 1.

∴ Ratio of radii = 4:1.

Answer 2

csa of one cone; πrl
Another cone csa; 2πrl
let slant height of first cone ; l
another ; 2l
πrl : 2(πrl)
Ratio of their radius is 1: 2