Question

Curved surface area of a cone is 308 cm² and its slant height is 14 cm. Find

(i) radius of the base and (ii) total surface area of the cone.

`["Assume "pi=22/7]`

 

Answer 1

(i) Slant height (l) of cone = 14 cm

Let the radius of the circular end of the cone be r.

We know, CSA of cone = πrl

`(308)cm^2=(22/7xxr xx14)cm`

`rArr r=(308/44)cm=7cm`

Therefore, the radius of the circular end of the cone is 7 cm.

 

(ii) Total surface area of cone = CSA of cone + Area of base

= πrl + πr²

`=[308+22/7xx(7)^2]cm^2`

= (308 + 154) cm²

= 462 cm²

Therefore, the total surface area of the cone is 462 cm².