Hi Rahul,
While creating the control, we can specify the dimension say 200x200, 400x.. . But at runtime the user has the flexibilty to change the window size at will. while resizing, the charts should update properly even if the window is resized to a rectangle. Please look at the image(third image) i have uploaded. I have tired using autoscale and contrainedScale featues but none of this give desired output.