Base of a conic solid
The planar region that forms the widest point of a conic solid; often labeled as the 'bottom' of the conic solid, it determines the exact shape of the conic solid.

Conic solid
The set of points between a point (the vertex) and a non-coplanar region (the base), including the point and the region.

Cylinder
The surface of a cylindrical solid whose base is a circle.

Cylindrical surface
The union of the bases and the lateral surface.

Diameter of a circle (or sphere)
The segment whose endpoints are points on a circle (or sphere) that contains the center of the circle as its midpoint; the length of that segment.

L.A.
Lateral area.

Lateral area
The area of the lateral surface of a solid.


Lateral surface
The surface not included in the base (s).

Oblique prism or cylinder
A non-right prism or cylinder.

Solid
The union of the surface and the region of space enclosed by a 3-D figure; examples: conic solid, cylindrical solid, rectangular solid.

Solid geometry
The study of figures in three-dimensional space.

Space
The set of all possible points; made up of infinite planes.

Surface
The boundary of a 3-D figure.

Surface area
The total area of the surface of a solid.

Unit cube
Unit of measuring volume.