Prove: If a quadrilateral is inscribed in a circle, then an exterior angle of the quadrilateral is congruent to its opposite interior angle.

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Which expression is rational? 6. , square root two, square root 14, square root 49

What is r i 4.5+10r=-6.5 with work pls