Question

A cone is made by rolling up a sector of central angle 120⁰ a) What is the ratio of radius and slant height of the cone? b) If the curved surface area of the cone is 108pi find the radius and slant height?​

Answer 1

Answer:

Step-by-step explanation:

Curved surface area of cone = πrl

πrl = 108 × 22/7

πrl = 339.4285714

Now Area of sector formed = CSA of cone

theta/ 360 ×πr^2 = πrl

120/360 × 22/7 ×r^2 = 339.4285714

r^2 = 324

r = 18 ------> 1

Now put the value of r in

rl = 108

18 ×l = 108

l = 6 -----> 2

so the ratio of radius is to slant height that is r : l = 3 : 1.