In the given figure AB||PQ||CD, AB = x units, CD= y units and PQ = z units, then 1/x + 1/y=_______
In Δ FDC and Δ FBA, ∠FDC = ∠FBA [As DC || AB] ∠DFC = ∠BFA [common angle] Hence, ∆FDC ~ ∆FBA by AA criterion for similarity. So, we have DC/AB = DF/BF z/x = DF/BF …. (1) In Δ BDC and Δ BFE…