What are the surface area and volume of a cylinder with a bottom radius of 1 decimeter and a square with its side expanded? As long as the first answer, give a reward, but I'm new here, by the way, tell me what 28.26x15 is equal to

What are the surface area and volume of a cylinder with a bottom radius of 1 decimeter and a square with its side expanded? As long as the first answer, give a reward, but I'm new here, by the way, tell me what 28.26x15 is equal to

The height of this cylinder is 2 × 3.14 × 1 = 6.28 (decimeter)
The volume of this cylinder is 3.14 × 1 × 6.28 = 19.72 (cubic decimeter)
The surface area of this cylinder
=6.28×6.28+3.14×1×1×2
=39.44+6.28
=45.72 (square decimeter)

When the side of a cylinder is unfolded, it is just a square. Its bottom surface area is 20 square decimeters. What is the surface area of the cylinder?

The bottom area is π R ^ 2 = 20 square decimeters,
When the side is unfolded, it is just a square, indicating that the perimeter and height of the bottom are equal
SO 2 π r = h, so the side area is (2 π R) ^ 2 = 4 π * π R ^ 2 = 4 π * 20 = 80 π square decimeter,
The surface area of the cylinder is = bottom area * 2 + side area = 20 * 2 + 80 π = 291.2 square decimeters
Don't understand can help you explain

A cylinder with a radius of 1 decimeter on its bottom and a square on its side. What is the surface area and volume of the cylinder?
Don't convert to meter

The side unfolds into a square
h = 2×3.14×0.1 = 0.628（m）
Surface area = 2 * 3.14 * 0.1 * 0.1 + 2 * 3.14 * 0.1 * 0.628
=0.457184 (M2)
Volume = 3.14 * 0.1 * 0.1 * 0.628 = 0.0394384 (M3)