The outside angle 15 of {HEAD ~ the base} 10 forming {TAIL ~ a junction} with the oblique side 12 remains rounded 
forming
The outside angle 15 of { HEAD ~ the base } 10 forming { TAIL ~ a junction } with the oblique side 12 remains rounded
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH