MathDB

circle chord

Source: flanders '99/2

September 27, 2005

Problem Statement

Let

C,D

be a diameter of the circle

C

and

[AB]

a chord with given length on this circle.

[AB]

neither coincides nor is perpendicular to

[AB]

. Let

C,D

be the orthogonal projections of

A

and

B

on

[MN]

and

P

the midpoint of

[AB]

. Prove that

\angle CPD

does not depend on the chord

[AB]

.

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