Question

The radius and slant height of a cone are In the ratio of 4 : 7. If its curved surface area is 792 cm², find its radius. (Use it 𝜋 = 22/7).

Answer 1

Given

Curved surface area = `pirl = 792`

Let the radius `(r) = 4x`

Height `(h) = 7x`

Now, CSA = 792

`22/7 xx "4x" xx 7x = 792`

⇒ `88x^2 = 792`

⇒ `x^2 = 792/88 = 9`

⇒ `x = 3`

∴ Radius = 4

= 4 × 3

= 12cm