Use to give the cosine of an angle.
In a right angled triangle, the cosine of an angle is the length of the adjacent side (A) divided by the length of the hypotenuse (H).
cosx = A/H
So for an example we could transpose the formula to find either A or H if we know the angle x.
A = H * cosx or H = A/cosx
In the software we would enter the following for the values where A is 15 and H is 30 and x is 60 degrees
=(COS(60))*30 and =15/(COS(60))