Solution: point C is CF⊥AB, vertical foot is F, and point MN is E.

Then CF=DB=50, CE=0.65, (2 points)

∫MN∨AB，

∴△CMN∽△CAB.

∴cecf=mnab(5 points)

∴AB=MN？ CFCE = 0. 16×500.65≈ 12.3。

The height of flagpole AB is about12.3m (8 points).