Geometry Diff is a required standard math course for the student to develop their thinking and reasoning abilities.  The course is designed around Euclidean Plane Geometry with the students using theorems, postulates and formulas to solve problems.  The development of logical sequence is stressed through deductive reasoning.  Geometric theorems are proven about angles, triangles, congruent triangles, similar triangles, parallel lines with transversals and quadrilaterals using deductive reasoning.  Topics covered are angles, congruence, parallel and perpendicular lines, quadrilaterals, triangles, circles, similarity, transformational geometry and coordinate geometry.  Constructions of geometric figures are stressed at the beginning of this class. Geometry is a system of organized information about size and shape properties of space and objects in space.  It is a basic part of other branches of mathematics and of other subjects such as architecture, engineering, astronomy, and physics.