Angle Addition Postulate and Bisector

Fill in the statement.

Fill in the reason.

• def. of midpoint

• def. of bisector

• def. of linear pair

• Angle Addition Postulate

• a. Symmetric Property b. Angle Addition Postulate c. Substitution Property d. Angle Addition Postulate e. Subtraction

• a. Reflexive Property b. Addition Property c. Angle Addition Postulate d. Angle Addition Postulate e. Substitution Property

• a. Reflexive Property b. Transitive Property c. Angle Addition Postulate d. Angle Addition Postulate e. Substitution Property

• x=3/17
• x=9
• x=3
• x= -3

x=3/17

x=9

x=3

x= -3

• x=3/17

• x=9

• x=3

• x= -3

What is reason 2?

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Angle JHG measures 161.

• m∠GHK=80.5,

  m∠KHJ=161

• m∠GHK=161,

  m∠KHJ=80.5

• m∠GHK=80.5,

  m∠KHJ=80.5

• m∠GHK=161,

  m∠KHJ=161

Given: m∠LAN = 30⁰ , m∠1 = 15⁰
Prove: AM bisects ∠LAN
Step 1: m∠LAN = 30⁰ 
Step 2: m∠1 + m∠2 = m∠LAN
Step 3: m∠1 + m∠2 = 30⁰
Step 4: m∠1 = 15⁰
Step 5: 15⁰ + m∠2 = 30⁰
Step 6: m∠2 = 15⁰
Step 7: m∠1 = m∠2
Step 8: ∠1 ≅ ∠2
Step 9: AM bisects ∠LAN
What is the justification for Step 9?

• Symmetric property of congruence

• Definition of angle bisector

• Addition property of equality

• Definition of congruent angles

If < ABC= 103⁰, find m< ABD

• 45

• 13

• 57

• 46