5.2
5.2. Proving that Lines are Parallel. A. B. C. D. ACD is an exterior angle. A & B are remote interior angles. m ACD is greater than m A . m ACD is greater than m B. 2. 1. 3. 4. 5. 6. 8. 7. 1 2 PQ ║ RS PQR RSP 3 4 QR ║ PS
5.2
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5.2 Proving that Lines are Parallel
A B C D ACD is an exterior angle. A & B are remote interior angles. mACD is greater than mA. mACD is greater than mB
2 1 3 4 5 6 8 7
1 2 PQ ║ RS PQR RSP 3 4 QR ║ PS PQRS is a parallelogram. Given Alt. int. s → ║ lines. Given Subtraction Property. Same as 2. A 4-sided figure with both pairs of opposite sides parallel is a parallelogram.
7 ways to prove lines parallel • AIP Alt Interior Angles ≅ • CAP Corresponding Angles ≅ • AEP Alt Ext Angles ≅ • SSISP same side interior angles supp parallel lines • SSESP same side exterior angles supp parallel lines • 2p3p two lines in a plane are both perpendicular to the same line they are parallel • Transversal of parallel if 2 lines are both parallel to the same line then they are parallel
