Question 24616
The surface area of a right circular cone is given by:
{{{S = (pi)Rs}}} Where: R is the radius and s is the slant height.
{{{S = (pi)(3)(5)}}}
{{{S = 15(pi)}}}square inches. If you use {{{(pi) = 3.14}}}, then,
{{{S = 47.1}}}square inches.

If you include the area of the base, then you add:
{{{B = (pi)R^2}}}
{{{B = 9(pi)}}}

Total surface area:

{{{S + B = 15(pi) + 9(pi)}}}
{{{S + B = 24(pi)}}} If {{{(pi) = 3.14}}}, then, 
{{{S + B = 75.36}}} square inches.