Congruence (geometry) - Definition of Congruence in Analytic Geometry

Definition of Congruence in Analytic Geometry

In a Euclidean system, congruence is fundamental; it is the counterpart of equality for numbers. In analytic geometry, congruence may be defined intuitively thus: two mappings of figures onto one Cartesian coordinate system are congruent if and only if, for any two points in the first mapping, the Euclidean distance between them is equal to the Euclidean distance between the corresponding points in the second mapping.

A more formal definition: two subsets A and B of Euclidean space Rn are called congruent if there exists an isometry f : RnRn (an element of the Euclidean group E(n)) with f(A) = B. Congruence is an equivalence relation.

Read more about this topic:  Congruence (geometry)

Famous quotes containing the words definition of, definition, congruence, analytic and/or geometry:

    Beauty, like all other qualities presented to human experience, is relative; and the definition of it becomes unmeaning and useless in proportion to its abstractness. To define beauty not in the most abstract, but in the most concrete terms possible, not to find a universal formula for it, but the formula which expresses most adequately this or that special manifestation of it, is the aim of the true student of aesthetics.
    Walter Pater (1839–1894)

    Mothers often are too easily intimidated by their children’s negative reactions...When the child cries or is unhappy, the mother reads this as meaning that she is a failure. This is why it is so important for a mother to know...that the process of growing up involves by definition things that her child is not going to like. Her job is not to create a bed of roses, but to help him learn how to pick his way through the thorns.
    Elaine Heffner (20th century)

    As for butterflies, I can hardly conceive
    of one’s attending upon you; but to question
    the congruence of the complement is vain, if it exists.
    Marianne Moore (1887–1972)

    “You, that have not lived in thought but deed,
    Can have the purity of a natural force,
    But I, whose virtues are the definitions
    Of the analytic mind, can neither close
    The eye of the mind nor keep my tongue from speech.”
    William Butler Yeats (1865–1939)

    The geometry of landscape and situation seems to create its own systems of time, the sense of a dynamic element which is cinematising the events of the canvas, translating a posture or ceremony into dynamic terms. The greatest movie of the 20th century is the Mona Lisa, just as the greatest novel is Gray’s Anatomy.
    —J.G. (James Graham)