Most trigonometry resources hand students a memory trick like SOH CAH TOA and move straight to calculation. The ratios appear as given facts, the calculator steps are practised until they stick, and the question "why does this actually work?" is left unanswered. Students who succeed can follow the procedure; fewer can explain what they are doing or adapt when a problem looks slightly different. This no-prep, self-paced package takes a different route. It starts by asking: why do right-angled tri