congruent
121Waring's problem — In number theory, Waring s problem, proposed in 1770 by Edward Waring, asks whether for every natural number k there exists an associated positive integer s such that every natural number is the sum of at most s k th powers of natural numbers… …
122Prototile — In a given set S of shapes, some shapes may be congruent to one or more others.A subset R of S is called a set of prototiles of S , if * the shapes in R are mutually non congruent * R is complete in the sense that each shape A in S is congruent… …
123Congruence relation — See congruence (geometry) for the term as used in elementary geometry. In abstract algebra, a congruence relation (or simply congruence) is an equivalence relation on an algebraic structure (such as a group, ring, or vector space) that is… …
124Parity (mathematics) — In mathematics, the parity of an object states whether it is even or odd. This concept begins with integers. An even number is an integer that is evenly divisible by 2, i.e., divisible by 2 without remainder; an odd number is an integer that is… …
125Shape — The shape (OE. sceap Eng. created thing ) of an object located in some space refers to the part of space occupied by the object as determined by its external boundary abstracting from other aspects the object may have such as its colour, content …
126Stellation — is a process of constructing new polygons (in two dimensions), new polyhedra in three dimensions, or, in general, new polytopes in n dimensions. The process consists of extending elements such as edges or face planes, usually in a symmetrical way …
127Rhombus — For other uses, see Rhombus (disambiguation). Rhombus Two rhombi Type quadrilateral, bipyramid Edges and vertices …
128Invalid proof — In mathematics, there are a variety of spurious proofs of obvious contradictions. Although the proofs are flawed, the errors, usually by design, are comparatively subtle. These fallacies are normally regarded as mere curiosities, but can be used… …
