Question 1036002
If you divide the length of the small side to the length of the long side you get 1/3 = .3333 = Tangent of the angle. Now you have to find the angle that its tangent is .3333.
Go this website: http://www.rapidtables.com/calc/math/Arctan_Calculator.htm
and type .33333 and click calculate to find the angle = 18.4333