I'm not a hundred percent sure but I think It would be a circle. Hope that helps.
When you horizontally cut a cylinder, you will see a circle as the resulting 2D shape. This circle is formed by the intersection of the plane (the cut) with the curved surface of the cylinder. The circle will have the same diameter as the base of the cylinder.
A circle !
A quadrilateral rectangle or a square
The shape of the cross section depends on the 3D object being sliced. For example, if you slice through a cylinder horizontally, the cross section would be a circle. If you cut through a cube diagonally, the cross section could be a triangle or a rectangle, depending on the angle of the cut. Thus, the specific 2D shape observed in the cross section varies based on the object's geometry and the orientation of the cut.
A cylinder is a 3d shape because you can see the in side of it.
a weird shape
You will see a rectangle
Go under the engine compartment and fairly in the center of the car you will see the starter which is a cylinder in shape.
This shape is known as a Conical Frustum. Please see the related link.
See the related links for a picture of this shape:See the related links for a PDF that shows you how to cut out this shape
A Cylinder?!
The term cut, in the 4 Cs of diamond valuation -- cut, colour, clarity and carat weight -- describes the shape of the finished stone.Following the link, below, you can see examples of a few fancy cuts:HeartRadiantMarquisePearOvalEmeraldIn most diamonds adverts, you'll see the round cut, which is common.According to the link below:"As a value factor, though, cut refers to a diamond's proportions, symmetry, and polish."