When the perpendicular lines from the axis are extended to intersect the asymptote, they mark off the lengths b'=21+1/21 , c'= 22 +1/22 ,d'=23+1/23. When the points b, c, and d are projected back down to the asymptote they mark off lengths, b"=(21+1/21)/2; c"=(22+1/22)/2; d"=(23+1/23)/2