Cylinder ‒ Stereometry

A right circular cylinder can be generated by rotating the rectangle A₁S₁S₂A₂ around an axis along one of its sides — in this case, along the line o = ← → S₁S₂. The rotation of vertices A₁ and A₂ forms the base edges of the cylinder, while the rotation of the line segments S₁A₁ and S₂A₂ creates the circular bases. The rotation of the line segment A₁A₂ generates the lateral surface of the cylinder. The surface of a closed cylinder consists of both bases (top and bottom) and the lateral area. The line o is referred to as the axis of the cylinder, and the various positions of the line segment A₁A₂ form the sides of the cylinder. The length of the line segment S₁S₂ is the cylinder's height, and the lengths of the segments S₁A₁ and S₂A₂ correspond to the cylinder's radius. The radius is half of the diameter. A cylinder whose height is equal to its diameter is called an equilateral cylinder.