This question is related to Rotating point feature symbols by intersect polyline in ArcGIS Desktop?, but my problem differs slightly.
I have a layer with polygons (nearly all rectangular) and a second one with points. The points are set in the middle of one of the sides of each polygon. I need to represent the points as arrows pointing directly into the polygon. So far I use an attribute of the point layer for rotation and fill the rotation in manually, but I was wondering, if I could derive the rotation value from the direction of the polygon segment automatically?
I use QGIS 2.18.16 on a Windows 7 PC.