This document provides an introduction to basic geometry concepts including 2D and 3D shapes. It defines plane figures as 2D shapes that appear flat, such as triangles, rectangles, squares, and circles. Solid figures are defined as 3D shapes that appear to have depth and stand on their own, including cubes, cylinders, rectangular solids, spheres, and cones. Examples of various 2D and 3D shapes are shown along with their defining properties.