This document defines and explains basic geometry terms related to lines, angles, triangles, quadrilaterals, circles, and other polygons. It includes definitions of line segments, rays, intersecting and parallel lines, acute, obtuse, right, and straight angles. It also defines scalene, isosceles, equilateral, right, obtuse, and acute triangles as well as perimeter and area formulas. Common quadrilaterals such as parallelograms, rectangles, rhombuses, squares, and trapezoids are defined along with their area formulas. Circles are described using terms like chord, diameter, radius, sector, circumference, and area. Finally, hexagons, octagons, and