In number theory, congruences provide a convenient way to describe divisibility properties. "a is congruent to b modulo m" simply means that m divides a - b.

The mathematical shorthand for this statement is "a ≡ b (mod m)". m is called the modulus of the congruence.

In plane geometry, curve* A is congruent to curve B if A can be transformed to B by means of rotation, translation (sliding), and/or reflection (flipping). Congruent polygons have identical side lengths and angle measures.

*A curve can be any two-dimensional shape, e.g. a polygon or a circle.

Con"gru*ent (?), a. [L. congruens, p.pr. of congruere: cf. F. congruent.]

Possessing congruity; suitable; agreeing; corresponding.

The congruent and harmonious fitting of parts in a sentence. B. Jonson.

Congruent figures Geom., concurring figures.

© Webster 1913.