I haven't done the math, but going out 5 feet is a decline of 2 feet.
This results in a slope of 21 degrees if my trig is correct.
Many places is steeper (going out 3 feet could be decline of 1-2 feet
in some places). This slope is about 18-33 degrees, in other places go
out 10 feet and go down 5 feet, this slope is 26 degrees.
This assumes all the trig I learned to become an engineer has actually
stayed with me 15 years later. Who wouldathunk?