Because they can be combined to form any polygon, triangles are by far the most important polygon to study. With a good base of knowledge of triangles, you can find out almost anything about any polygon.

Every triangle has six main parts, its three sides and three angles. A triangle can be classified by either of these criteria--sides or angles. In addition to falling into a certain category based on sides or angles, triangles can also qualify as special triangles by meeting more specific requirements. Special triangles such as equilateral, isosceles, and right triangles, have very precise properties and characteristics that help us draw conclusions about unknown figures. In the following lessons, we'll take a look at some general characteristics of all triangles, and then move to examine the characteristics of special triangles.