Question 954689
The frustum is that portion of a solid which lies {{{between}}} two parallel planes cutting the solid and has a top base radius {{{r[1]}}}, bottom base radius {{{r[2]}}}, height {{{h}}}, and slant height {{{s}}}.

slant height ({{{s}}}) could be found using a formula:

{{{s=sqrt((r[1]-r[2]))^2+h^2)}}}

The LATERAL surface area, {{{not}}} including the top and bottom circles, is

{{{LA=pi*(r[1]+r[2])s}}}

{{{LA=pi*(r[1]+r[2])sqrt((r[1]-r[2]))^2+h^2)}}}

and the TOTAL surface area will be greater for a top base and bottom base area which are {{{r[1]^2*pi}}} and {{{r[2]^2*pi}}}

{{{TA=pi*((r[1]+r[2])sqrt((r[1]-r[2]))^2+h^2)+r[1]^2*pi+r[2]^2*pi}}}