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MathNet 2024-part-01 — 168 problems (EN–VI) Question 46

Math Olympiad Vault · MathNet 2024-part-01 — 168 problems (EN–VI)

Question 46

Inside an isosceles triangle $ABC$ ($AB = BC$), a point $D$ is chosen so that $\angle ADC = 150^\circ$. On the segment $CD$, a point $E$ is chosen so that $AE = AB$.
Prove that if $\angle BAE + \angle CBE = 60^\circ$, then $\angle BDC + \angle EAC = 90^\circ$.