Question 1206900
 
given:


external radius {{{r[e]=0.45m}}}
height {{{h=1.75m}}}
 {{{20mm}}} thick={{{0.02m}}}


=>internal radius {{{r[i]=0.54m-0.02m=0.43m}}}


Total surface area 

{{{SA = 2pi*r(r[i] + h)}}}, where {{{r[i]}}} is the radius of the base and {{{h}}} is the height of the tank.

{{{SA =2pi*0.43m(0.43m+1.75m)}}}

{{{SA =5.889857906950144m^2}}}

{{{SA =5.89m^2}}}