In this activity, we will be looking at the fact that certain angles are equal to each other when a line is drawn across two parallel lines.

Look at the diagram below to see which of the eight angles are equal to each other.  

All the a angles are equal to each other and all the b angles are equal to each other.

Remember also that aº + bº = 180º as they are the angles on a straight line.

That's a lot to remember, so feel free to click on the red help button on the screen to see this page again