Geometry Problem 1285
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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Geometry Problems
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Triangle
Quadrilateral
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Angles
90 degrees
60 degrees