In the diagram the lines AB and CD are crossed by the transversal EF. Click and drag any of the blue points so that AB is parallel to CD.

- Write down the names of one pair of alternate angles, one pair of cointerior angles and one pair of corresponding angles on the lines AB and CD.
- With reference to the terms 'alternate angles', 'cointerior angles' and 'corresponding angles', list three different conditions that exist when AB and CD are parallel.