Cylindrical section property: examples

• This ellipse is the intersection of a right circular cylinder and a plane that makes a minimal angle of 30 degrees to the axis of the cylinder.
• If a plane makes a minimal angle of 30 degrees to the axis of any circular cylinder, the intersection will be the same ellipse.
• If a plane makes an angle of 90 degrees with the axis of a cylinder, the intersection will be a circle, a special case of an ellipse.
• The surface of liquid in a cylindrical drinking cup will have an elliptical border.
• If a cardboard mailing tube is cut by a plane, the cut end of the tube will be elliptical.