Justifications for Proofs

Choose the correct definition, postulate, or theorem for the following statement

• Definition of Congruence

• Definition of Midpoint

• Segment Addition Postulate

• Definition of Linear Pair

Choose the correct definition, postulate, or theorem for the following statement

• Definition of Congruence

• Definition of Midpoint

• Definition of Segment Bisector

• Segment Addition Postulate

Which postulate or definition states that

m∠ADB + m∠BDC = m∠ADC?

• Segment Addition Postulate

• Angle Addition Postulate

• Definition of Angle Bisector

• Definition of Congruence

If ∠A and ∠B are complementary,
then m∠A + m∠B = 90°.

• Definition of Supplementary Angles
• Angle Addition Postulate
• Definition of Right Angle
• Definition of Complementary Angles

If ∠1 and ∠2 are supplementary,
then m∠1 + m∠2 = 180°.

• Definition of Supplementary Angles
• Angle Addition Postulate
• Vertical Angles Theorem
• Definition of Linear Pair

If m∠1 = m∠2 and m∠2 = m∠3, then m∠1 = m∠3.

• Transitive Property of Congruence

• Symmetric Property of Equality

• Reflexive Property of Equality

• Transitive Property of Equality

If K is between L and M, then LK + KM = LM.

Why?

• Segment Addition Postulate

• Substitution

• Angle Addition Postulate

• Definition of a midpoint

Using the figure above, what is the reason for the following:

∠1 ≅ ∠3

• Angle Addition Postulate

• Definition of Vertical Angles

• Definition of Complementary Angles

• Definition of Congruence

What is the reason for the statement below?
Given: m∠1 = 63
m∠1 + m∠2 = 90
Prove: 63 + m∠2 = 90

• Reflexive Property of Equality
• Symmetric Property of Equality
• Transitive Property of Equality
• Substitution Property of Equality

What is the justification?

• Angle Addition Postulate

• Definition of Perpendicular Angles

• Definition of a Right Angle

• Definition of Complementary Angles