# Proofs : Quadrilaterals

1- Prove that in a cyclic quadrilateral we have opposite angles supplementary without introducing the center of the circle.

2- Prove that a quadrilateral is paralleogram if it is simple and opposite angles are congurent.

© BrainMass Inc. brainmass.com October 9, 2019, 5:53 pm ad1c9bdddfhttps://brainmass.com/math/discrete-math/proofs-quadrilaterals-71542

#### Solution Preview

Please see the attached file for the complete solution.

Thanks for using BrainMass.

1- prove that in a cyclic quadrilateral we have opposite angles supplementary without introducing the center of the circle.

Solution:

Consider a cyclic quadrilateral ABCD

Draw AC and BD.

Now, ...

#### Solution Summary

Quadrilateral proofs are provided. The solution is detailed and well presented. Diagrams are included.

$2.19