Cylinder (geometry)
A cylinder (from Greek κύλινδρος – kulindros, "roller, tumbler") is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder. The surface area and the volume of a cylinder have been known since deep antiquity.
In differential geometry, a cylinder is defined more broadly as any ruled surface spanned by a one-parameter family of parallel lines. A cylinder whose cross section is an ellipse, parabola, or hyperbola is called an elliptic cylinder, parabolic cylinder, or hyperbolic cylinder respectively.
The open cylinder is topologically equivalent to both the open annulus and the punctured plane.
Read more about Cylinder (geometry): Common Use, Volume, Cylindric Section, Other Types of Cylinders, About An Arbitrary Axis, Projective Geometry
Famous quotes containing the word cylinder:
“The outline of the city became frantic in its effort to explain something that defied meaning. Power seemed to have outgrown its servitude and to have asserted its freedom. The cylinder had exploded, and thrown great masses of stone and steam against the sky.”
—Henry Brooks Adams (1838–1918)