It is a resource that never fails in interior design. If you have doubts when it comes to decorating your house, you can always go safe with a symmetrical space, since our brains are programmed to feel this as harmonious and pleasing to the eye. Of course, this also applies to curtains. When you have a window on a sloping roof, installing a traditional bedroom window curtains would not work since there is no space for the open curtain to be outside the window.
Another option in a window like this would have been to install a roller blind or a blind. When you have a bay window or cantilevered window (which many confuse with a bow window) there are several options of bedroom window curtains that you could use, but they can be summarized in two: Install the curtains inside the window, like the image above, or install them outside the window.
In some cases you can also use a mixture of both, that is, curtains inside and through the window frame. When you have a round window or with any other shape out of the ordinary, a practical alternative is to use Roman shades (roller), in this way you keep the shape on the frame. In addition, as these bedroom window curtains can be attached with Velcro are easier to install.