Question 1160453



given:
 {{{r=4cm}}} 
{{{h=12cm}}}

 total surface area open at one end:

If you are asked to find the surface area of a cylinder open at one end , then you want to find the areas of the one ends (which is {{{r^2*pi}}}) and the curved surface (which is {{{2r*pi*h}}}) .
 
{{{A=r^2*pi+2r*pi*h}}}

{{{A=(4cm)^2*pi+2*4cm*pi*12cm}}}

{{{A=16*pi*cm^2+96*pi*cm^2}}}

{{{A=112*pi*cm^2}}}->exact

{{{A=351.86*cm^2}}}-> approximately