The arcs intersect at {HEAD ~ point} 82, and the exit apertures of both cusps are defined by {TAIL ~ the line} 76 82 which lies in the plane of reflectors 73 and 75 
The arcs intersect at { HEAD ~ point } 82 , and the exit apertures of both cusps are defined by { TAIL ~ the line } 76 82 which lies in the plane of reflectors 73 and 75
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH