//For Swift 3: M_PI is depreciated now Use Double.pi
let radians = atan2f(Float(yourView.transform.b), Float(yourView.transform.a));
let degrees = radians * Float(180 / Double.pi)
//For Swift 4:
let radians = atan2(yourView.transform.b, yourView.transform.a)
let degrees = radians * 180 / .pi