You don't even know how to do it yourself and you wanna be a teacher. Delete this video it will make people think they're making a mistake! The final answer is "14.14" and idk how you got 70m
you are the one who is making a mistake please delete this comment it will make people think that this method is wrong. he got 70 by square rooting (50^2+30^2)- 2x50x30xcos120 if you are wondering how he got 120 he subtracted 60 from 180.