Angles in Parallel Lines

Parallel lines never meet and stay the same distance apart. When a transversal (crossing line) cuts through parallel lines, different angle relationships are formed.

Types of Angles in Parallel Lines include:

Corresponding Angles

• Corresponding Angles can be found by looking for an  F-Shape
• These angles are equal.

Alternate Angles

• Alternate Angles can be found by looking for an  Z-Shape
• These angles are equal.

Co-Interior (Supplementary) Angles

• Co-Interior (supplementary) Angles can be found by looking for an  C-Shape
• The angles add up to $180\degree$.

Example: Finding Missing Angles

Find angles p and q in diagram below. You must give reasons for your answers

1. For $p$ :

   • Use vertically opposite angles for p: $$p = 134 \degree$$

2. For $q$:

   1. Use corresponding angles (F-Shape) to find the angle on the same line as $q$ to be $134\degree$

   2. Now use angles on a line sum to $180\degree$ to find $q$ $\to$ $q = 180\degree - 134\degree$ $\therefore \quad q = 46\degree$

Final Answer:  $p = 134 \degree$,  $q = 46\degree$.