
In ∆ AOB, OF is bisector of ∠ AOB
∴ OA / OB = AF / B ...... (1) (by angle bisector theorem)
In ∆ BOC, OD is bisector of angle ∠ BOC.
∴ OB / OC = BD / CD ....... (2)(by angle bisector theorem)
In ∆ AOC , OE is bisector of angle∠ AOC.
∴ OC / OA = CE / AE ....... (3)(by angle bisector theorem)

∴ BF × AE × CD = AF × CE × BD