Geometry - 2 Column Proofs

If <M = <L then <L = <M

• Transitive POE
• Substitution POE
• Symmetric POE
• Reflexive POE

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

What is the justification (reason)?

• Reflexive Property
• Transitive Property

What is the justification (reason)?

• reflexive property
• definition of segment bisect
• definition of a midpoint

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

• Definition of Complementary Angles
• Addition Property 

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

• Reason
• Given

If a=b and b=c then a=c 

• Transitive Property
• Reflexive Property

What is the reason?

• Definition of congruence
• Definition of Angle

What is the reason?

• Definition of Complementary
• Definition of supplementary