MathDB

56

Part of 1985 IMO Longlists

Problems(1)

Determine the angle as a function

Source:

9/14/2010
Let ABCDABCD be a rhombus with angle ∠A=60∘\angle A = 60^\circ. Let EE be a point, different from DD, on the line ADAD. The lines CECE and ABAB intersect at FF. The lines DFDF and BEBE intersect at MM. Determine the angle ∠BMD\angle BMD as a function of the position of EE on AD.AD.
functiongeometryrhombuscircumcircle