The figure below shows a cyclic quadrilateral ABCD with perpendicular diagonals at P. Lines H_{1}PE_{3}, H_{2}PE_{4}, H_{3}PE_{1}
, and H_{4}PE_{2} are perpendicular to AB, BC, CD, and AD, respectively. Prove that the quadrilateral E_{1}E_{2}E_{3}E_{4}
is a rectangle.

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Geometry Problems

Open Problems

Visual Index

Ten problems: 1411-1420

All Problems

Triangle

Circle

Cyclic Quadrilateral

Perpendicular lines

Rectangle

Cyclic Quadrilateral with Perpendicular Diagonals

Brahmagupta

GeoGebra

HTML5 and Dynamic Geometry

iPad Apps

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