Quote:
Originally Posted by Unregistered
As I hiker I sometimes want to calculate the difficulty of a climb. I know how to use rise over run to get the percent of an incline. How do I convert that percent to degrees WITHOUT a scientific calculator? For example, yesterday I went up a trail with a 38 percent incline (1000 ft. gain over 1/2 mile).

You either need a scientific calculator (Windows has one hiding in the Windows apps, and there are many Javascript ones on the web) or a trig table. You need the arc whose tangent is 0.38. The inverse function is called arctangent, abbreviated ATAN, ATN or TAN with 1 superscript.
The answer is 20.8°