Angles in Polygons & Parallel Lines Quiz

1. Two straight lines cross. One of the four angles formed is $70^{\circ}$. What is the angle vertically opposite it?

• A. $70^{\circ}$
• B. $110^{\circ}$
• C. $180^{\circ}$
• D. $35^{\circ}$

2. A transversal crosses two parallel lines. Two angles form a 'Z' shape between the parallel lines. What is their relationship?

• A. They sum to $360^{\circ}$
• B. They are equal (alternate angles)
• C. They sum to $180^{\circ}$
• D. They are equal (corresponding angles)

3. What is the sum of the interior angles of a regular octagon ($n = 8$)?

• A. $720^{\circ}$
• B. $1080^{\circ}$
• C. $1440^{\circ}$
• D. $360^{\circ}$

4. A regular polygon has an exterior angle of $30^{\circ}$. How many sides does it have?

• A. 10
• B. 12
• C. 15
• D. 9

5. Two co-interior angles between a pair of parallel lines are $(2x + 10)^{\circ}$ and $(x + 20)^{\circ}$. What is the value of $x$?

• A. $x = 50$
• B. $x = 60$
• C. $x = 40$
• D. $x = 30$