Question

Hurry please!!! Fast response

Answer 1

Answer:

A.

$SA= \frac{2}{3} \pi rl+16 \pi r^2$

Step-by-step explanation:

Surface area of the original cone

$SA= \pi r l + \pi r^2... (1)$

When, radius is quadrupled and slant height is reduced to one sixth

$i. e. \: \:r = 4r\: \: \&\:\: l= \frac{1}{6}l$

Plug the above values of r and $l$ in equation (1), new surface area becomes:

$SA= \pi (4r)\times \frac{1}{6} l+ \pi (4r)^2$

$SA= \frac{4}{6} \pi rl+16 \pi r^2$

$\huge \purple {\boxed {SA= \frac{2}{3} \pi rl+16 \pi r^2}}$