Since every corner window is different in design, it will be necessary for you to determine the best method of mounting blinds in your corner windows.
This will give you some ideas to use in making determinations for your installation. In the illustration below, if the blind is wide enough to require a center support bracket, it will likely need to be mounted to the ceiling. The method shown below provides the greatest amount of privacy and the least gap between blinds. Round your measurements to the nearest 1/8".
Note how one blind head rail overlaps the other. If the windows are identical in size, then one blind will be narrower than the other.
Use Chart 1 to determine the head rail depth for the product you are purchasing.
Order the blinds as Inside Mount.