Definition:Base


 * Geometry:
 * The base of a geometric figure, for example:
 * Base of a triangle (Plane geometry)
 * Base of a parallelogram (Plane geometry)
 * Base of a segment of a circle (Plane geometry)
 * Base of a cone (Solid geometry)
 * Base of a right circular cone (Solid geometry)


 * Number theory:
 * Number Base (Number theory and arithmetic)

Also see
The concept of a Basis may also be relevant.