Question

Please answer this question...the answer is....πr(l+r/4)....
But i want to know....how this answer came?
First and the Proper answer will be the brainliest....

Answer 1

Given radius of  a cone = r/2 and Slant height = 2l.

We know that TSA of a cone:

$= \ \textgreater \ \pi r(l + r)$

$= \ \textgreater \ \pi ( \frac{r}{2} )[2l + \frac{r}{2}]$

$= \ \textgreater \ \pi \frac{r}{2} (2l) + \pi \frac{r}{2} ( \frac{r}{2} )$

$= \ \textgreater \ \pi r l + \frac{ \pi r^2}{4}$

$= \ \textgreater \ \pi r(l + \frac{r}{4} )$



Hope this helps!

Answer 2

Hi,

Please see the attached file!



Thanks