High alpine pyramidal peaks formed by cirque-carving glaciers very commonly (not always) have three nearly symmetrical faces and corresponding ridges spaced roughly 120 deg. apart. This is easily visible in a random search of alpine topo maps, Google Earth etc. Without conducting an exhaustive statistical study, it in fact seems to be the most common alpine shape.
Is there some principle of physics or geology that causes the erosion of the cirques to form in this regular pattern?