The surface area of a cube is simply the area of one face multiplied by 6, since all of the 6 faces are exactly the same, therefor:
Surface area = 5*5*6 = 150 ft^2
Use the definition of tangent
or inv tangent (arctan or atan)
tan(theta) = opposite side/ adjacent side
the vertical rise would be the opposite side, the horozontal distance would be the adjacent side
let rise = y
let distance= x
x=2y
so tan(theta) = y/2y
tan(theta) = 1/2
theta = atan(1/2)
grab a handy dandy calculator, unless you know this conversion off the top of your head
You can let the sides be a and b. You can then use the Law of Sines to create an equation relating the two sides and the angles opposite them, and finally isolate a/b.