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# Geometry Problem 1285

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### Elements: Triangle, Quadrilateral, 60, 150, 90 Degree Angles, Congruence,
Measurement.

In a quadrilateral ABCD, angle A = 60, angle B= 150 and angle C = 90
degrees, so that AC = BD. Prove that
2AD = 6AB = 3CD. (Trigonometry is not allowed.)

*This entry contributed by Sumith Peiris, Moratuwa, Sri Lanka.*

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Triangle

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90 degrees

60 degrees

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