Analytic geometry uses algebraic methods to study and prove geometric problems using coordinates. This chapter discusses using coordinate proofs to prove theorems from geometry. It provides instructions on how to construct a coordinate proof by drawing and labeling a diagram, listing given information, stating what will be proved, using algebra to add to the diagram and prove the statement, and writing a conclusion. Common algebraic methods used in proofs include the distance formula, identifying parallel and perpendicular lines, and finding midpoints. Examples provided are proving properties of right triangles, trapezoids, and triangles.