I understand the equation to find the coefficient of friction. fr = a/b a -> height of the ramp b -> length of the base of the ramp. But i understand that it's also possible to find friction coefficient using angle of elevation of the ramp. So if i know the angle of elevation and the height of the ramp, is it possible to still find the friction coefficient? In other words, is there an alternate formula (other than fr = a/b) ??