Parallel line proofs

Lessons

• Introduction
  Relationships between lines and angles

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• 1.
  What is the value of x if $\overline {AB}$ $\parallel$ $\overline {CD}$ ?
  a)

  
  
  
  
  
  b)

  
  
  
  
  
  c)

  
  
  
  
  

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• 2.
  Determine if enough information is given to prove $p \parallel$ $q$ State the postulates or theorems you use in your answers.
  a)

  
  
  
  
  
  b)

  
  
  
  
  
  c)

  
  
  
  
  
  d)

  
  
  
  
  

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• 3.
  Prove that if two lines are cut by a transversal so the alternate exterior angles are congruent, then the lines are parallel. (Prove the Alternate Exterior Angles converse)

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• 4.
  Write a two-column proof.
  a)

  Given: $m \parallel$ $n$, $\angle 1$ $\cong$$\angle 2$
  Prove: $s \parallel$ $t$
  
  
  
  
  b)

  Given: $\angle 1$ $\cong$$\angle 2$, $\angle 1$ $\cong$$\angle 3$
  Prove: $\overline {AB}$ $\parallel$ $\overline {CD}$
  
  
  
  

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