This document provides definitions and key information about basic geometry terms including lines, angles, triangles, quadrilaterals, circles, perimeters, and areas. It defines different types of lines like segments, rays, intersecting, perpendicular, and parallel lines. It also defines acute, obtuse, right, straight, complementary, supplementary, vertical, and adjacent angles. Additionally, it outlines the characteristics and definitions of right, obtuse, acute, scalene, isosceles, and equilateral triangles. Finally, it defines quadrilaterals like trapezoids, parallelograms, rectangles, rhombuses, and squares and gives the formulas to calculate their perimeters and areas.