MathDB

Two orthogonal circles

Source: MMC 2013

May 31, 2013

geometry proposedgeometry

Problem Statement

ABCD

is quadrilateral inscribed in a circle

EF

.Lines

AB

and

CD

intersect at

E

and lines

AD

and

BC

intersect at

F

. Prove that the circle with diameter

EF

and circle

\Gamma

are orthogonal.

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