The area of the curved surface of a cone of radius 2r and slant height 1/2 , is A. πrl B. 2πrl C. 1/2 πrl D. π(r+l)r ​

Question

The area of the curved surface of a cone of radius 2r and slant height \(\frac{1}{2}\), is 

A. πrl 

B. 2πrl 

C. \(\frac{1}{2}\)πrl 

D. π(r+l)r

Answer 1

Option : (A)

Radius of cone = 2r 

Slant hight = \(\frac{1}{2}\)

Area of curved surface = πrl

= \(\frac{22}{7}\times\)2r \(\times\)\(\frac{1}{2}\)

= πrl