Dynamic Geometry Problem 1465: Tangential Quadrilateral, Incenter, Inscribed Circle, Equal Sum of Areas.
Let ABCD be a tangential quadrilateral and P be the center of the inscribed circle (see the figure below). if S1 = area APB, S2 = area BPC, S3 = area PCD and S4 = area APDH, prove that S1 + S3 = S2 + S4.
Static Diagram of Geometry Problem 1465
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Ten problems: 1411-1420
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