For this case, we have that by definition:
Be a rectangular triangle and an "x" angle.

CO is the leg opposite the angle and H the hypotenuse
We want to find the Sine (S) according to the figure shown:

We do not have the opposite leg, we must apply the Pythagorean theorem, which states:

Where:
H: Hypotenuse
CO: Opposite leg
CA: Adjacent leg
In this case, we must find CO:

Where:

Substituting:

So, we have:

Answer:

