The basics of geometry, lines, angles, planes, rays, are a great beginning. Geometry, which means earth measure is used to measure anything on earth. No matter what size a rectangle is, whether it be a computer chip, an Olympic-sized swimming pool, or a city block, you can always find its area by multiplying length by width. Readers also learn about polygons, triangles, circles, congruent figures, symmetry, and cones, as well as areas, perimeters,...