In the case of a right triangle
[tex]\tan (\theta)=\frac{O}{A},\cos \theta=\frac{A}{H}[/tex]
Then,
[tex]\begin{gathered} \Rightarrow\theta=\arctan (\frac{O}{A}) \\ \text{and} \\ \theta=\arccos (\frac{A}{H}) \end{gathered}[/tex]
Therefore, in a diagram,
