BASE, in Geometry, the lowest side of the perimeter of a figure: Thus, the base of the triangle may be said of any of its sides, but more properly of the lowest, or that which is parallel to the horizon. In rectang-
led triangles, the base is properly that side opposite to the right angle.
BASE of a Solid Figure, the lowest side, or that on which it stands.
BASE of a Conic Section, a right line in the hyperbola and parabola, arising from the common intersection of the secant plane and the base of the cone.