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
