How to apply the triangle angle sum theorem.
How to derive the formula to find the sum of angles in any polygon.
How to identify supplementary and complementary angles.
How to determine the relationship between the side inequalities and angle inequalities in a triangle.
How to find the sum of the exterior angles in a polygon and find the measure of one exterior angle in an equiangular polygon.
How to find the measure of one angle in any equiangular or regular polygon.
How to identify a segment from the vertex angle in an isosceles triangle to the opposite side.
How to relate corresponding altitudes, medians and angle bisectors in similar triangles.
How to determine if two triangles in a circle are similar and how to prove that three similar triangles exist in a right triangle with an altitude.
How to classify a triangle based on its side lengths and angle measures.
How to define an angle of elevation or an angle of depression.
How to define isosceles triangles, their components and how to determine their properties.
How to calculate the area of any triangle using two sides and an included angle.
How to derive the area of a triangle formula using the rectangle area formula.
How to calculate the measure of an inscribed angle.
How to define exterior angles and their remote interior angles and how to prove their properties.
How to define corresponding angles and their special properties.
How to label an angle bisector; how to use an angle bisector to find a missing variable.
How to duplicate an angle using a compass and straightedge.
How to prove that an angle inscribed in a semicircle is a right angle; how to solve for arcs and angles formed by a chord drawn to a point of tangency.