Each side creates {HEAD ~ an angle} between {TAIL ~ about 50°} and about 70° from the base to a side 
Each side creates { HEAD ~ an angle } between { TAIL ~ about 50 ° } and about 70 ° from the base to a side
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH