Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

square



  1. A quadrilateral with four equal sides that meet at right angles.

  2. To square something is to multiply it by itself. To take the square root is the reverse process. A square number is the square of a whole number. A well known formula for the difference of squares is a2 - b2 = (a + b)(a - b). This formula enables some otherwise difficult calculations to be done easily in the head. For example, 43 × 37 = (40 + 3)(40 - 3) = 402 - 32 = 1600 - 9 = 1591.

Related category

   • POLYGONS