How to define alternate interior angles and their special properties.
How to define exterior angles and their remote interior angles and how to prove their properties.
How to describe same side interior and same side exterior angles and their special properties.
How to construct parallel lines using three different methods.
How to define isosceles triangles, their components and how to determine their properties.
How to strategize about solving a problem with trapezoidal arches.
How to prove that opposite angles in a cyclic quadrilateral are congruent; how to prove that parallel lines create congruent arcs in a circle.
How to identify all of the special properties of parallelograms and use them to solve problems.