How to identify, define, and label rays and opposite rays.
Drawing the ray diagrams for convex and concave lenses.
How to relate the sides of an angle bisected and the lengths of the opposite side.
How to label an angle bisector; how to use an angle bisector to find a missing variable.
How to simplify rational expressions.
How to identify all of the special properties of parallelograms and use them to solve problems.
How to find the resultant of two forces when they are parallel, opposite, or perpendicular in direction.
How to identify a segment from the vertex angle in an isosceles triangle to the opposite side.
How to define an altitude and draw them on acute, right, and obtuse triangles.
How to graph y = tan(q) for one or more periods.
How to prove that opposite angles in a cyclic quadrilateral are congruent; how to prove that parallel lines create congruent arcs in a circle.