Question

the radius oand slant height of a cone are in the ratio 4:7 if its curved surface area is 792 cm find its radius

Answer 1

Solution:-
The ratio of the radius and height of the cone is 4 : 7.
Let the radius of the cone be 4x and the height be 7x
So, 
Curved surface area of the cone = πrl
792 = 22/7*4x*7x 
x² = (792*7)/(22*4*7)
x² = 9
x = √9
x = 3 cm
So, the radius of the cone = 4 × 3 = 12 cm.
Answer