Right Angles- All right angles are congruent.
Straight Angles- All straight angles are congruent.
Congruent Supplements- Supplements of the same angle, or congruent angles, are congruent.
Congruent Complements- Complements of the same angle, or congruent angles, are congruent.
Linear Pair- If two angles form a linear pair, they are supplementary.
Vertical Angles- Vertical angles are congruent.
Triangle Sum- The sum of the interior angles of a triangle is 180º.
Exterior Angle- The measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.
The measure of an exterior angle of a triangle is greater than either non-adjacent interior angle.
Base Angle Theorem-
(Isosceles Triangle) If two sides of a triangle are congruent, the angles opposite these sides are congruent.
Base Angle Converse-
(Isosceles Triangle) If two angles of a triangle are congruent, the sides opposite these angles are congruent.