Reciprocal figures

(Geom.) two figures of the same kind (as triangles, parallelograms, prisms, etc.), so related that two sides of the one form the extremes of a proportion of which the means are the two corresponding sides of the other; in general, two figures so related that the first corresponds in some special way to the second, and the second corresponds in the same way to the first.

See also: Reciprocal

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.