1, straight tube.

A right cylinder, also known as a right cylinder or cylinder, has the following characteristics:

(1) The two bottoms of a straight cylinder are circles with equal radii.

(2) The connecting lines between the centers of the two bottom surfaces of the right cylinder and the two bottom surfaces are perpendicular to each other.

(3) The side spread of a straight cylinder is rectangular.

2. Tilt the cylinder.

Inclined cylinders have the following characteristics:

(1) The two bottom surfaces of an oblique cylinder are circles with the same radius.

(2) The connecting line between the centers of the two bottom surfaces of the oblique cylinder is not perpendicular to the two bottom surfaces.

(3) The lateral expansion of the oblique cylinder is a parallelogram.

Related information:

1. The geometric figure formed by the straight line of one side of the rectangle as the rotation axis and the curved surface formed by the rotation of the other three sides is called a cylinder, that is, one side AG of the rectangle ADD'G is the axis, and the other three sides rotate once.

Among them, AG is called the axis of the cylinder, AG is called the height of the cylinder, and the side not perpendicular to the axis is called the generatrix of the cylinder wherever it rotates. The two circles formed by the rotation of DA and D'G are called the bottom surface of the cylinder, and the curved surface formed by the rotation of d' d is called the side surface of the cylinder.

2. There is a fixed line and a moving line in the same plane. When the plane rotates once around this fixed line, the surface formed by this moving line is called the rotating surface, this fixed line is called the axis of the rotating surface, and this moving line is called the generatrix of the rotating surface. If the generatrix is a straight line parallel to the axis, then the generated surface of revolution is called a cylindrical surface.