Angles, parallel lines and polygons Quiz

1. Two angles on a straight line are $(2x+10)^\circ$ and $(x+20)^\circ$. Find $x$.

• A. $50$
• B. $40$
• C. $30$
• D. $10$

2. Parallel lines are crossed by a transversal. One angle is $72^\circ$. What is its co-interior angle?

• A. $72^\circ$
• B. $18^\circ$
• C. $288^\circ$
• D. $108^\circ$

3. What is the sum of the interior angles of a hexagon?

• A. $540^\circ$
• B. $720^\circ$
• C. $360^\circ$
• D. $1080^\circ$

4. A regular polygon has an interior angle of $140^\circ$. How many sides does it have?

• A. $8$
• B. $10$
• C. $9$
• D. $12$

5. Triangle angles are $40^\circ$ and $65^\circ$. What is the exterior angle at the third vertex?

• A. $75^\circ$
• B. $105^\circ$
• C. $115^\circ$
• D. $25^\circ$