Question

The radius and slant height of a cone are in ratio 4:7. If its curved surface area is 792 cm^2, find its height.

Answer 1

Let the radius of the cone = 4x
and the slant height of the cone = 7x
Given, curved surface area of the cone = 792
= πrl = 792
= (22/7) * 4x * 7x = 792
= 88 * 2 = 792
= x2 = 792/88
= x2 = 9
= x2 = √9
= x = 3
So, the radius of the circle = 4x = 4 * 3 = 12 cm

Answer 2

Answer:

Step-by-step explanation:

Given :-

Ratio of radius and slant height = 4 : 7

Curved Surface Area = 792 cm²

To Find :-

Radius of cone

Formula to be used :-

Curved surface area of cone = πrl

Solution :-

Let the radius of cone (r) = 4x cm

And the slant height of the cone (l) = 7x cm  

Curved surface area of cone = πrl

πrl = 792 cm²    

⇒ 22/7 × 4x × 7x = 792

⇒ x² = 792/22 × 4

⇒ x² = 9  

⇒ x = 3 cm

Radius of the cone = 4 × 3 = 12 cm

Hence, Radius of cone is 12 cm.