How to solve proportions.
How to solve a simple proportion.
Understanding the laws of definite and multiple proportions.
How to prove two triangles are similar using a line parallel to a base.
How to set up percent problems as proportions.
Solving percent problems using proportions
Overview of similarity: congruent angles, proportional corresponding sides
How to define direct variation.
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 define indirect variation.
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.
Short, helpful video on ACT prealgebra by top ACT prep instructor, Devorah. Videos are produced by leading online education provider, Brightstorm.