Inscribed Quadrilateral


Tennille Rushin


Problem:  To prove that opposite angles of an inscribed quadrilateral are supplementary.


First construct a circle.









Then add four points on the circle and create an inscribed quadrilateral.




Construct a segment AC.  This will create two triangles. 


Measure angle DAB and angle BCD.

Angle DAB and BCD added up to 180 degrees proving they are supplementary angles.  Angle DAB is 1/2 of arc BCD and angle BCD is 1/2 of arc BAD.  In conclusion anytime you have an inscribed quadrilateral, (inside the circle), opposite angles will be supplemental.



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