Geometry Problem 1286. Elements: Triangle, Quadrilateral, 60, 135, 105 Degree Angles, Congruence, Measurement.


In a quadrilateral ABCD, angle  A = 60, angle B= 135 and angle C = 105 degrees, so that AC = BD. Prove that Formula to proof.
This entry contributed by Sumith Peiris, Moratuwa, Sri Lanka.

Geometry Problem 1286: Triangle, Quadrilateral, 60, 135, 105 Degree Angles, Congruence, Measurement