Review the basic knowledge on Triangle:

Terms

1. Acute angle: 

2. Obtuse angle: 

3. Right angle:
   

4. Straight angle: 

5. Vertical angles

6. Complementary angles

7. Supplementary angles 

8. Isosceles triangle

9. Equilateral triangle

Relationship of Angles Formed by Parallel Lines

1. Alternate interior angles

2. Alternate exterior angles
   

3. Interior angles on the same sides of transversal

4. Corresponding angles

Angle – Measure – Sum Principles

1. Theorem 1. The sum of the measures of the angles of a triangle equals ___ ?

2. Theorem 2. The measure of each exterior angle of a triangle equals ___ ?

3. Theorem 3. The sum of the measures of the exterior angles of a triangle equals ___ ?

4. Theorem 4. The four angles in the figure below have the following relationship: ___ ?