The document discusses different types of triangles classified by their angles and sides. It describes right triangles which have a 90 degree angle, acute triangles with angles all less than 90 degrees, obtuse triangles with an angle greater than 90 degrees, and equilateral triangles with all three angles congruent. Triangles are also classified as scalene, isosceles, or equilateral based on their side lengths. Students work in groups to measure angles and sides of triangles and classify them. Special triangle theorems are presented including the sum of interior angles equaling 180 degrees, the exterior angle theorem, and the isosceles triangle theorem. Examples of homework problems involving triangle angle measures are provided.