1. 1 Press Ctrl-A ©G Dear2008 – Not to be sold/Free to use Angles between Parallel Lines Stage 6 - Year 11 Mathematic (Preliminary)

2. 2 Alternate angles are equal. Notice that the angles makes a Z shape. Alternate Angles Transversal momo nono Therefore m o = n o Angles between parallel lines 1

3. 3 Alternate Angles Alternate angles are equal. momo 60 o Therefore m o = 60 o Angles between parallel lines 2

4. 4 Notice that the angles makes a F shape. Corresponding angles are equal. Corresponding Angles Therefore m o = n o momo nono Angles between parallel lines 3

5. 5 Corresponding angles are equal. Corresponding Angles Therefore m o = 70 o momo 70 o Angles between parallel lines 4

6. 6 Notice that the angles makes a C shape. Corresponding angles add to 180 o. Co-interior Angles Therefore m o + n o = 180 o momo nono Angles between parallel lines 5

7. 7 Corresponding angles add to 180 o. Co-interior Angles Therefore m o + 120 o = 180 o momo 120 o Angles between parallel lines 6 -120 o m o = 60 o

8. 8 Tests for Parallel Lines To prove that lines are parallel we show that: 1. Alternate angles are equal or 2. Corresponding angles are equal or 3. Co-interior angles add to 180 o Angles between parallel lines 4