Mathematics

Ashlee Haynes

29 April, 15:02

Angle and Becky each completed a separate proof to show that the measures of vertical angles AKG and HKB are equal. Who completed the proof incorrectly? Explain.

Angie's Proof

Statement

Justification

1. Segment GH intersects segment AB at K 1. Given

2. m AKG + m GKB 180°

2. Definition of Supplementary Angles

m. GKB + m2HKB 180°

3. m AKG + m2 GKB = m GKB + m2HKB 3. Substitution Property

4. m AKGm HKB

4. Subtraction Property

Becky's Proof

Statement

Justification

1. Segment GH intersects segment AB at K 1. Given

2. m AKG + m GKB = 180°

m GKB + m2HKB - 180°

2. Angle Addition Postulate

3. m AKG + m. GKB = m GKB + m2HKB 3. Substitution Property

4. m AKGm HKB

4. Subtraction Property