1) [tex]6*12*4 - 4*4*4 = 4*(6*12-4*4) = 4*56=224m^2[/tex]
2) [tex]6*6*6+\frac{8*6*6}{3}=312ft^2[/tex]
3) [tex]3^2\pi(\frac{8}{3}+8) = \frac{9*8*4\pi}{3} = 96\pi m^2[/tex]
