{HEAD ~ A first flange} extends perpendicularly from {TAIL ~ the first side} of the upper surface of the longitudinal plate and an end wall extends perpendicularly from each one of two ends of the bottom surface 
extends perpendicularly from
{ HEAD ~ A first flange } extends perpendicularly from { TAIL ~ the first side } of the upper surface of the longitudinal plate and an end wall extends perpendicularly from each one of two ends of the bottom surface
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH