| Opposite angles are equal |

| Alternate angles when a line is drawn to intersect parallel lines are equal. To recognise when this rule can be used look for 'Z' shapes. |

| Supplementary or complementary angles when a line is drawn to intersect parallel lines add to 180 Degrees, soAgain look for 'Z' shapes. The supplementary angles are on the same side of the 'Z'. |

| Corresponding angles can be 'slid' along a line between parallel lines. Corresponding angles are equal. |

| Angles on a straight line add up to 180 Degrees. |