One Step Geometry Proofs

If M is the midpoint of AB, then AM = MB

• Addition POE
• Def. of Midpoint 
• Reflexive POE
• Symmetric

If <1 and <2 are complementary, then m<1 + m<2 = 90

• Addition POE
• Subtraction POE
• Def of right angle
• Def of Complementary Angles

IF <ABC ≅ <DEF, then m<ABC = m<DEF

• Reflexive POE
• Addition POE
• Def. of congruent angles
• Def. of right angles

If X is between R & T on a line,
then RX + XT = RT

• Addition POE
• Substitution POE
• Angle Addition Post.
• Segment Addition Post.

What is the reason?

• Definition of Complementary
• Definition of 180 
• Definition of supplementary
• Angle Addition

What is the reason?

• Definition of complementary

• Definition of supplementary

Which property justifies the next step?

• Definition of linear pair
• Definition of supplementary angles
• Congruent supplements thm
• Linear pair postulate

Which property justifies the next step?

• Segment addition postulate
• Definition of an angle bisector
• Angle addition postulate
• Definition of right angles

What is always the 1st statement in reason column of a proof?

• Prove
• Given
• Reason
• Statement

What is the REASON for Statement #2?

• Given
• Definition of Complementary Angles
• Substitution Property
• Reflexive Property of Congruence