As a maths teacher it often struck me that, every time we had to actually give a lesson on Pythagoras or trigonometry, it was because the students didn't understand formulas.
In that case, they should be learning about formulas (how to substitute values, how to rearrange formulas, ...) rather than memorising step by step instructions on how to solve questions. Those step by step instructions are difficult to remember, get all mixed up with a 1000 other things learnt by rote and put a barrier between students and real maths -- even if they pass exams.
On the other hand: for students who do understand formulas... A picture and a labeled diagram should be enough
a2 + b2 = c2
All the instructions you need are in that formula! So, if you are stuck on Pythagoras: learn about formulas.
That's the philosophy behind this website.