The surface area of 1 is increased by two inner sides.

The total area of the two inner sides is 2×d×h, where d is the diameter of the bottom surface and h is the height.

That is, 2dh=40, so dh=20 (square centimeter).

Because d= 10cm, h=2cm.

So the original surface area of the cylinder is two bottom surfaces+side surfaces.

That is, s table = 2 π (d/2) 2+π DH = 2 π× 52+π×10× 2 = 50 π+20 π = 70 π = 70× 3.14 = 219.8 (square centimeter).

The lateral area of cylinder s =πDH = 2πRH = 150 (square centimeter)

Since R = 4cm, h= 18.75/π.

So the cylinder volume V column = SH = π R2× h = π R2×18.75/π =18.75r2 =18.75x4 = 300 (cubic centimeter).

Xiaoyou answered, I hope the answer will help you.