Original surface area = bottom area *2+ surrounding area

Late surface area = bottom area * area around the section 6+3.

Surrounding area = perimeter * bottom height, while the surrounding area of the third part = surrounding original area.

Therefore, the increased area = bottom area *6- bottom area *2= bottom area *4.

Let the radius x,

6.4=4*(x^2*3. 14)

X 2 = 0.5 square decimeter, which is approximately equal to.

Volume = bottom area * height =0.5*250= 125 cubic decimeter.