Definitions
An angle measures 90 degrees if and only if it's a _________
Right angle, Definition of a right angle
If two angles form a right angle, then they are complementary
Complement Theorem
If the measure of angle R = the measure of angle S, then angle R is congruent to angle S
Definition of Congruence
_______ lines form right angles
Perpendicular, Definition of perpendicular
If two angles are vertical, then they are congruent
Vertical angles theorem
Given the diagram (look at the white board)
Vertical angles theorem
Two angles are ________ if and only if the sum of their measures is 90 degrees
Complementary, Definition of complementary angles
If two angles form a linear pair, then they are supplementary
Linear pair/supplement theorem
Given the diagram (look at the whiteboard):
If n is perpendicular to m, then angle 1 is a right angle
Definition of perpendicular
Two angles are _________ if and only if the sum of their measures is 180 degrees
Supplementary, Definition of supplementary angles
If angle A is complementary to angle B AND angle C is complementary to angle B, then angle A is congruent to angle C
Congruent complements theorem
Look at the white board
Linear pair/supplements theorem
An ____________ divides an angle into two equal parts
Angle bisector, Definition of an angle bisector
If angle A is supplementary to angle B AND angle C is supplementary to angle B, then angle A is congruent to angle C
Congruent supplements theorem
Given the diagram (look to the white board)
Angle addition postulate