This is a right triangle, so this is a triangle in which one angle is a right angle, that is, 90 degrees. For a given angle α, sinα follows the following relation:
[tex]sin \alpha = \frac{O}{H}[/tex]
So, in the triangle above:
[tex]O = 7[/tex] [tex]H = 17.46[/tex]
Thus, the result applying the previous equation is given by: