Geometry Essentials For DummiesCritical theorems for geometry proofs The principles and formulas you need to know Key concepts in quick, focused lessons All you need to get in shape for geometry This practical, friendly guide focuses on critical concepts taught in a typical geometry course. Get a handle on the basics from lines, segments, and angles to vertices, altitudes, and diagonals. Learn the properties of triangles, parallelograms, circles, and cylinders. Master the skills