Answer:
Sine
Explanation:
As per the trigonometric ratios "sine" of any angle is the ratio of the side which is exactly opposite to the angle and the hypotenuse.
The formula is

The hypotenuse is the longest side in any right triangle. The side containing the angle is called the base. The side which is opposite to the angle is called the perpendicular. So basically it is " Sine" of any angle is ration of "perpendicular " to the "Hypotenuse"