[tex]sine=\dfrac{opposite}{hypotenuse}\\\\tangent=\dfrac{opposite}{adjacent}[/tex]
[tex]\sin B=\dfrac{b}{a};\ \tan C=\dfrac{c}{b}\\\\\sin B\cdot\tan C=\dfrac{b}{a}\cdot\dfrac{c}{b}=\dfrac{c}{a}\\\\\sin C=\dfrac{c}{a};\ \tan B=\dfrac{b}{c}\\\\\sin C\cdot\tan B=\dfrac{c}{a}\cdot\dfrac{b}{c}=\dfrac{b}{a}[/tex]
