Trigonometry Fun

During this Lockdown period the wonderful youtuber 3blue1brown has created a youtube series called “Lockdown Maths” that have been a glorious set of lectures. These are two worksheets I created that directly use puzzles that are mentioned in this lecture: https://www.youtube.com/watch?v=QvuQH4_05LI&t=1501s

They are beautiful geometric proofs of some often (and less often) used Trigonometric Identities. The techniques used in the first sheet will help greatly in the second sheet and lead me to a fantastic aha moment.

For example in sheet 1 you end up proving pythagoras’ theorem from a trig identity – something that feels like the wrong way round!