Like other areas of mathematics, geometry is a continually growing and evolving field. Computers, technology, and the sciences drive many new discoveries in mathematics. For geometry, the areas of quantum computers, computer graphics, nanotechnology, crystallography, and theoretical physics have been particularly relevant in the past few years. There have been considerable developments in the field of geometry since the first edition of "The Facts On File Geometry Handbook" was published. An ideal primer for middle and high school students on the subject of geometry, this revised edition highlights new developments while expanding on the material in the first edition. More than 300 new glossary terms have been added as well as new biographies, events, charts, tables, theorems, and photographs and line illustrations. New and revised entries include: Algebraic equation; Calipers; Coloring; Devil's pitchfork; Hausdorff distance; John Hubbard; Isometric perspective; Gottfried Wilhelm Leibniz; Magic square; Monstrous Moonshine Madness; Isaac Newton; Grigory Perelman; Root snail; School Mathematics Study Group (SMSG); Sudoku square; Wheel of Theodorus; and, Windmill Theorem.