Let ABCD be quadrilateral inscribed in a circle with center O. Prove that sum of the angles AOB and COD = 180°.

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- August 17th 2008, 05:19 AMfardeen_genIn quadrilateral, prove sum of angles AOB and COD =180...?
Let ABCD be quadrilateral inscribed in a circle with center O. Prove that sum of the angles AOB and COD = 180°.

- August 17th 2008, 05:49 AMSoroban
Hello, fardeen_gen!

Is there a typo ... or omitted information?

. . The statement is not true . . .

Quote:

Let be a quadrilateral inscribed in a circle with center

Prove that: .

Code:`A * * * B`

o o

* \ / *

* \ / *

\ /

* \ / *

* *O *

* / \ *

/ \

* / \ *

* / \ *

o o

D * * * C

For the statement to be true,

. . and must be perpendicular diameters ... always!

- August 17th 2008, 05:53 AMfardeen_gen
I posted the question as it was given in the source. Thanks for the counter example.

- August 17th 2008, 05:56 AMCaptainBlack