Parallelogram view using UIBezierPath

Question

I am trying to create custom parallelogram view using UIBezierPath but not getting a perfect one.

Following is my custom view code

class CustomView: UIView {
    override func draw(_ rect: CGRect) {
        let offset  = 60.0;
        let path = UIBezierPath()

           path.move(to: CGPoint(x: self.frame.origin.x + CGFloat(offset), y: self.frame.origin.y))
           path.addLine(to: CGPoint(x: self.frame.width + self.frame.origin.x  , y: self.frame.origin.y))
           path.addLine(to: CGPoint(x: self.frame.origin.x + self.frame.width - CGFloat(offset) , y: self.frame.origin.y + self.frame.height))
           path.addLine(to: CGPoint(x: self.frame.origin.x, y: self.frame.origin.y + self.frame.height))


        // Close the path. This will create the last line automatically.
         path.close()
        UIColor.red.setFill()
        path.fill()

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = path.cgPath
        self.layer.mask = shapeLayer;

    }
}

And i create the view using

let customView = CustomView()
customView.frame = CGRect(origin: CGPoint(x: 10, y: 20), size: CGSize(width: 250, height: 250))
self.view.addSubview(customView)

But i got the view like this and it is not a perfect parallelogram.