Now, ZC a ZF = (ZO2CF + 8) a (O2FC - Fa); and as ZO2CF = ZO2FC, we have Z0 a ZF = 8 + Fs. As 8 and F3 both are known, call their ... Also since C a F = 3 + F , and C + F = 180Ad - 6, we find 180Ad - 6 + 8 + Fa C = aa tan #4 (C + F). , from which C becomes known. ... In January a part of the line from Kennewick down the Columbia was opened and freight train service inaugurated, now reaching to Lyle.