K, I assume you either are too young to have had trig yet, or don't understand trig. So go to this web site.
http://www.carbidedepot.com/formulas-trigright.asp
Where it says side a, put in the contol throw in inches.
Where it says side b. put in the chord, or lenght of the control surface, from font to back, measuered in inches. You'll have to measure this yourself.
Hit calculate.
The degrees you want is 'Angle A'
For example, if you put in a control throw of 1" for a 3" cord control surface, you should get 18.4 degrees.