In an isoceles triangle ABC, AB = AC. The bisector AD of angle A meets the side BC at D. The line perpendicular to AD through D meets AB at F and AC produced at E. Perpendiculars from B and D to AC are respectively BM and DN. If AE = 2016 units, find the length MN.
In an isoceles triangle ABC, AB = AC. The bisector AD of angle A meets the side BC at D. The line perpendicular to AD through D meets AB at F and AC produced at E. Perpendiculars from B and D to AC are respectively BM and DN. If AE = 2016 units, find the length MN.