Question

What is the surface area of a cone when the slant height is 6 mm and the diameter is 4 mm?
A. 12 mm2
B. 24 mm2
C. 31.4 mm2
D. 50.24 mm2

Answer 1

Diameter of cone = d = 4mm

So,

Radius of cone = r = 2mm

Slant Height = l = 6mm

Surface Area = A = ?

formula for the surface area of cone:

A= pi r(r+l)

Using the values, we get:

A= pi (2)(2+6)=16 pi mm²

so the correct answer is D