In order to calculate the sine, cosine and tangent of angle A, we need to know the following:
The sine relation is the length of the opposite side to the angle over the length of the hypotenuse;
The cosine relation is the length of the adjacent side to the angle over the length of the hypotenuse;
The tangent relation is the length of the opposite side to the angle over the length of the adjacent side to the angle.
Knowing that, we have:
[tex]\begin{gathered} \sin (A)=\frac{BC}{AB}=\frac{4}{5} \\ \tan (A)=\frac{BC}{AC}=\frac{4}{3} \\ \cos (A)=\frac{AC}{AB}=\frac{3}{5} \end{gathered}[/tex]
