c o t α = c o s α s i n α c o t α = b c c o s α s i n α = b c a c = b a ↓ c o t α = c o s α s i n α {\displaystyle {\begin{aligned}cot\alpha ={\frac {cos\alpha }{sin\alpha }}\\cot\alpha ={\frac {b}{c}}\\{\frac {cos\alpha }{sin\alpha }}={\frac {\frac {b}{c}}{\frac {a}{c}}}={\frac {b}{a}}\\\downarrow \\cot\alpha ={\frac {cos\alpha }{sin\alpha }}\\\end{aligned}}}
