IMO 1984 LL MOR39

Let ABC be an isosceles triangle, AB = AC, ngleA = 20◦. Let

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IMO 1984 LL MOR39

Origin: MOR

Problem

Let ABC be an isosceles triangle, AB = AC, \angleA = 20◦. Let D be a point on AB, and E a point on AC such that \angleACD = 20◦and \angleABE = 30◦. What is the measure of the angle \angleCDE?