freeform window polygonal: After inserting - there will be displayed a 2D elevation over the wallopening in 2D - to turn off later. You can here drag the outer corners to the wanted maximal measures (A+B) and then drag the inner-polygonepoints wherever you want within the outer rectangele. Avoid small segments. Then You can drag in vertival and horizontal divisors and lengthen them in Your elevation as You need it or change the angle of each element. Then You can drag in rectangulear windows into the freeform up to 10 times. (You should construcht rectangular devisors for it before - to situate the casements correct later.) All elements will be put together automaticly und all holes will be cut out automatic. All you see in the 2D - elevation drawing will appear in 3D and the most of the operations you cam make in the groundfloor-2D-Elevation is also possible in 3D and a real elevation -view. a short Video-tutorial: https://www.youtube.com/watch?v=HJLPn90GrFQ&feature=youtu.be