1) Let's analyze those statements according to the Parallelism Postulates/Theorems.
8) If m∠4 = 50º then m∠6 =50º
Angles ∠4 and ∠6 are Alternate Interior angles and Alternate Interior angles are always congruent
So m∠4 ≅ m∠6
9) If m∠4 = 50, then m∠8 =50º
Angles ∠4 and ∠8 are Corresponding angles and Corresponding angles are always congruent
10) If m∠4 = 50º, then m∠5 =130º
Angles ∠4 and ∠5 are Collateral angles and Collateral angles are always supplementary. So
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