Question

Find the total surface area of a cone of radius 2r and slant height l by 2

Answer 1

Given, radius of the cone, $R=2r$

Slant height of cone, $L=$ $\frac{l}{2}$

Total surface area of cube = πRL

= π ×2r$\times \frac{l}{2}$

= π ×r$\times l$

$=\pi rl$