Question

A circular sheet of radius 18 cm is divided into 9 equal sectors find the measure of the central angle of a sector find the slant height of a cone which can be made by sector find the lateral surface area of the cone does formed

Answer 1

(a) central angle of a sector , θ = 360°/number of divisions of circular sheet

= 360°/9 = 40°

(b) slant height of cone which can be made by a sector, l = radius of circular sheet = 18cm

(c) radius of cone = r

we know, θ = l/r

⇒40° × π/180° = 2πR/r

⇒2π/9 = 2π × 18cm/r

⇒r = 2cm

hence, radius of cone is 2cm.

now lateral surface area of cone = πrl

= 22/7 × 2 × 18cm

= 792/7 cm

= 113.14 cm

Hope it will help you

Plz mark it as brainliest