[tex]\bf tan(\theta)=\cfrac{y}{x}\\\\
-------------------------------\\\\
\begin{array}{clclll}
(\frac{3}{5}&\ ,\ &\frac{4}{5})\\
\uparrow &&\uparrow \\
x&&y
\end{array}\qquad tan(\theta )=\cfrac{\frac{4}{5}}{\frac{3}{5}}\implies tan(\theta )=\cfrac{4}{5}\cdot \cfrac{5}{3}\implies tan(\theta )=\cfrac{4}{3}[/tex]
