Question

what is the total surface area of a cone whose radius =r/3 and slant height =31?

Answer 1

Please see the attachment

Answer 2

Answer:  The area of the cone is $\dfrac{22r}{21} (\dfrac{93+r}{3} ) sq. units$

Step-by-step explanation:

Radius of the cone = $\dfrac{r}{3}$

Slant height of the cone = 31

As we know  the total surface area of a cone is

$T.S.A. = \pi r(l+r) = \dfrac{22}{7}\times \dfrac{r}{3} \times (31+\dfrac{r}{3} )\\\\\\=\dfrac{22r}{21} (\dfrac{93+r}{3} ) sq. units$

Hence, the area of the cone is $\dfrac{22r}{21} (\dfrac{93+r}{3} ) sq. units$