The two longer sides constitute a pair of {HEAD ~ straight parallel primary locating sides} while the four shorter sides constitute pairs of {TAIL ~ secondary locating sides} extending at obtuse angles from each end of each primary locating side 
The two longer sides constitute a pair of { HEAD ~ straight parallel primary locating sides } while the four shorter sides constitute pairs of { TAIL ~ secondary locating sides } extending at obtuse angles from each end of each primary locating side
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH