How to solve a simple proportion.
How to define the law of sines.
How to define and use the law of cosines.
How to prove two triangles are similar using a line parallel to a base.
How to determine if two triangles are similar using a shortcut.
How to relate corresponding altitudes, medians and angle bisectors in similar triangles.
How to relate the sides of an angle bisected and the lengths of the opposite side.
How to identify the centroid and the way it divides each of the medians.
How to define a secant; how to find the length of various secants in circles.
How to identify if two figures are similar.