Question 970869
we have a 3, 4, 5 right triangle where side 4 is the set, side 3 is the run and side 5 is the travel.  We need to find the acute angles in this triangle.
Let angle A be the angle opposite side 4(set) and angle B be opposite side 3(run).  Then,
sin(-1) = 4/5 = 53.13 degrees = angle A
sin(-1) = 3/5 = 36.87 degrees = angle B
now
sin(A) = set / travel
set = travel * sin(53.13) = 5 * 0.799998928 = 3.99999464 approx 4