1. Proving Lines Parallel
We need to show congruent alternate interior angles, corresponding angles or alternate exterior angles. 6 C B D A 3 2 8 4 5 7 1 E F

2. Statement Reason 1. Given
Pg. 5 #4
Statement
Reason
1. Given
2. A segment bisector divides a segment into two congruent parts
3. Vertical angles are congruent
5. CPCTC
6. Two lines cut by a transversal that form congruent alternate interior angles are parallel

3. Statement Reason 1. Given 2. Given 3. Reflexive postulate 5. CPCTC
Pg. 5 #6
Statement
Reason
1. Given
2. Given
3. Reflexive postulate
5. CPCTC
6. Two lines cut by a transversal that form congruent alternate interior angles are parallel

4. Statement Reason 1. Given 2. Given
Pg. 5 #7
Statement
Reason
1. Given
2. Given
3. Angles opposite congruent sides of a triangle are congruent
4. Substitution Postulate
5. Two lines cut by a transversal that form congruent alternate interior angles are parallel

5. Statement Reason 1. Given 2. Given
Pg. 5 #9
Statement
Reason
1. Given
2. Given
3. Angles opposite congruent sides of a triangle are congruent
4. Substitution Postulate
5. Two lines cut by a transversal that form congruent corresponding angles are parallel

6. Statement Reason 1. Given 2. Given
Pg. 6 #25
Statement
Reason
1. Given
2. Given
3. Parallel lines cut by a transversal form congruent alternate interior angles
4. Reflexive Postulate
6. CPCTC
7. CPCTC
8. Two lines cut by a transversal that form congruent alternate interior angles are parallel