{HEAD ~ The plane} of {TAIL ~ reflectors} 73 and 75 then makes with the horizontal an angle α/2 equal to half the maximum solar altitude angle 
of
{ HEAD ~ The plane } of { TAIL ~ reflectors } 73 and 75 then makes with the horizontal an angle α/2 equal to half the maximum solar altitude angle
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH