Leo is a Stone Age, geometry genius. His cat, Pallas, is not. In this innovative series, which supports STEM fields, Leo identifies six key geometric concepts and puts them to use in his prehistoric world. Together, Leo and Pallas look at the historic, technological, and real-world applications of lines, spheres, circles, triangles, squares, and cubes. Fun characters combine humor with reference information and diagrams to help readers understand geometric principles and mathematical concepts.