A straight curve that has no ends. It has no width and continues without end in both directions.

A location.

Contains the endpoints and all points between the endpoints.

Indicates that designated geometric qualities are equal. Geometrically identical.

Part of a line with one endpoint--the beginning point, called the origin--and extends indefinitely in one direction. Also known as a half line.

Two rays of opposite directions that lie on the same line (rays that are collinear) and that share a common endpoint.

When two geometric figures have points in common.

A flat surface like a tabletop that has no thickness and that continues without limit in the two dimensions that define the plane. Determined by three noncollinear points, two lines that intersect at one point and/or two parallel lines.

Lines that are not in the same plane. Never parallel and do not intersect.

When two rays have a common endpoint and point in opposite directions; has a measure of 180°

Has measure that are greater than 90° and less than 180°.

When the sum of the measures of two angles is 180°.

A triangle in which all the angles measure equal.

A triangle in which the measure of at least two angles are equal.

A triangle in which the lengths of all sides are equal.

A triangle in which all of the sides have different lengths.

A line that cuts or intersects one or more other lines in the same plane.

Angles on opposite sides of the transversal.

A geometric solid determined by two parallel planes that intersect all the elements of a closed cylindrical surface.

A cylinder whose base is a circle.

A cylinder whose bases are not perpendicular to the sides.

Equals one third the product of the area of the base and the height.

Perfectly round, three-dimensional shape.

An unbroken connection of points.