Complex sentence: Double-square and triple-square drives are 2 or 3 squares superimposed (respectively), forming an 8-pointed or 12-pointed star--in other words, 2 or 3 Robertson squares superimposed at 45 ° or 30 ° rotation.
Split into simpler sentences: Double-square and triple-square drives are 2 or 3 squares superimposed (respectively), forming an 8-pointed or 12-pointed star. In other words, 2 or 3 Robertson squares superimposed at 45 ° or 30 ° rotation.