Angles

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 180 degree 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.