How to resize control with rotated in ViewModel - wpf

Question

... I can't speak english...
I have a problem.
I want to resize after rotate using 8 ResizeThumb.(like PowerPoint)
But when I applied RotateTransform(orgin = 0.5), Resize method is strangely work.
Item ViewModel ViewModel has properties(X, Y, Angle, Width, Height) like this.
private double _X;
public double X
{
get
{
return_X;
}
set
{
value = Math.Round(value);
if(_X == value) { return; }
_X = value;
RaisePropertyChanged("X");
}
}
... and Y, Angle, Height, Width.
And I tried Binding like this.
Angle is binding at RotateTransform.
X, Y is binding at Canvas.Left/Top or TranslateTransform.
But both case strangely work.
So when I calculate X,Y after rotate, I think calculate angle together.
public void ResizeTopCenter(DragDeltaEventArgs e)
{
Matrix m = Matrix.Identity;
m.Rotate(Angle * Math.PI/180);
Point rotated = m.Transform(new Point(e.HorizontalChanged, e.VerticalChange));
// little bit different every direction.
ViewModel.X += rotated.X;
ViewModel.Y += rotated.Y;
ViewModel.Height += rotated.Y;
}
Another way
Canvas.SetTop(this.designerItem, Canvas.GetTop(this.designerItem) + (this.transformOrigin.Y * deltaVertical * (1 - Math.Cos(-this.angle))));
Canvas.SetLeft(this.designerItem, Canvas.GetLeft(this.designerItem) - deltaVertical * this.transformOrigin.Y * Math.Sin(-this.angle));
... strange as expected.
I can't write full source because I was off work.
Had suffered for eight hours, tomorrow is also continuing.
Please help me.
thank you.
and I'm sorry to read strage english.