5.1 - Interior angles
5.2 - Exterior angles
5.3 - Angles on parallel lines
5.4 - Pythagoras (finding the hypotenuse)
5.5 - Pythagoras (finding the shorter side)
5.6 - Trigonometry (finding the missing lengths)
5.7 - Trigonometry (finding the missing angles)
5.8 - Exact trigonometric values (video coming soon)