Geometry is the study of points, lines, angles, and plane figures such as triangles, circles, and quadrilaterals. The student is taught to write formal proofs and to apply formulas involving perimeters, area, volumes, and surface areas. Basic principles of two and three dimensional figures, algebraic skills, and coordinate geometry will be used in problem solving situations. Trigonometry is introduced and algebraic concepts such as factoring and two-variable equations are applied to geometric situations. A main purpose of the study of geometry is the development of reasoning ability.