BBC4y
Angles made by parallel lines
Corresponding angles are equal. The lines make an F shape. Notice that the F shape can be upside down or back to front. We've already seen that intersecting lines create vertically opposite angles ...
BBC3y
Intersecting and parallel lines
When two lines intersect, the opposite (X) angles are equal. On parallel lines, alternate (Z) angles are equal. On parallel lines, corresponding (F) angles are equal. On parallel lines ...