Find Alternate and Corresponding Angles on Parallel Lines

In this activity, we will learn about parallel lines.

Parallel lines run in the same direction and are marked by arrowheads, as above.  They never meet.

Parallel lines that are intersected by an oblique line give rise to sets of equal angles.

The two angles marked in diagram (a) are equal.         

They are corresponding angles and can be found in an F-shape which is rotated. The F-shape can be upside down or back to front - as in the small diagram below.

Can you find three other pairs of corresponding angles? 

The two angles in diagram (b) are equal and are alternate angles. 

These lines can be found in a z-shape which can also be back to front - as shown below.

In this activity, we are going to use these two rules of parallel lines to work out the missing values of angles.

Are you ready? You can check back to these rules at any point by clicking on the red button on the right of the activity screen.