Write a two-column proof

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Presentation transcript:

Write a two-column proof EXAMPLE 1 Write a two-column proof Write a two-column proof for the situation in Example 4 on page 107. GIVEN: m∠ 1 = m∠ 3 PROVE: m∠ EBA = m∠ DBC STATEMENT REASONS 1. m∠ 1 = m∠ 3 1. Given 2. m∠ EBA = m∠ 3 + m∠ 2 2. Angle Addition Postulate 3. m∠ EBA = m∠ 1 + m∠ 2 3. Substitution Property of Equality

Write a two-column proof EXAMPLE 1 Write a two-column proof 4. m∠ 1 + m∠ 2 = m∠ DBC 4. Angle Addition Postulate 5. m∠ EBA = m∠ DBC 5. Transitive Property of Equality

GUIDED PRACTICE for Example 1 1. Four steps of a proof are shown. Give the reasons for the last two steps. GIVEN : AC = AB + AB PROVE : AB = BC STATEMENT REASONS 1. AC = AB + AB 1. Given 2. AB + BC = AC 2. Segment Addition Postulate 3. AB + AB = AB + BC 3. ? 4. AB = BC 4. ?

GUIDED PRACTICE for Example 1 ANSWER GIVEN : AC = AB + AB PROVE : AB = BC ANSWER 1. AC = AB + AB 2. AB + BC = AC 3. AB + AB = AB + BC 4. AB = BC Given Segment Addition Postulate Transitive Property of Equality Subtraction Property of Equality STATEMENT REASONS