MATHEMATICS ENCYCLOPEDIA

The word geometry is derived from the Greek words "geo" meaning "earth" and "metron" meaning "measuring". Thus geometry means earth measurement. Euclid was the first Greek mathematician who initiated a new way of thinking the study of geometry. Axioms: The basic facts which are taken for granted, without proof, are called axioms. Theorems: The conclusions obtained through logical reasoning based on previously proved results and some axioms constitute a statement which is known as a theorem or proposition. Point: A point is represented by a fine dot. Plane: The surface of a smooth wall or the surface of a sheet of paper or the surface of a smooth black board are close examples of a plane. Line: If we fold a piece of paper, the crease in the paper represents a geometrical straight line. Line segment:  A line segment is a part of a line that is bounded by two distinct points, and contains every point on the line between its endpoints.

Matrix: A matrix is an ordered rectangular array of numbers or functions. The numbers or functions are called the elements or the entries of the matrix. Order of a matrix: A matrix having m rows and n columns is called a matrix of order m*n or simply m*n matrix ( read as m by n matrix ). Types of matrix:   Column matrix: A matrix is said to be a column matrix if it has only one column. Row matrix: A matrix is said to be a row matrix if it has only one row. Square matrix: A matrix in which the number of rows are equal to the number of columns, is called a Square matrix. Thus an m*n matrix is a Square matrix if m = n. Also called as Square matrix od order n. Diagonal matrix: A Square matrix is a diagonal matrix if all its non diagonal elements are zero. Scalar matrix: A diagonal matrix is a scalar matrix if its diagonal elements are equal. Identity matrix: A Square matrix in which elements in the diagonal are all 1 and rest are all zero is called identity matrix. Z