Answer with Explanation:
The Statement is False,which is :Adjacent (or side-by-side) angles of a quadrilateral in a circumscribed circle are always supplementary.
The correct statement is:
The Sum of Opposite pair of angles of angles of a quadrilateral in a circumscribed circle are always supplementary.
For, example,Consider a circumscribed Quadrilateral A B CD, having center O.
Then , 1. →∠A + ∠C=180°
2.→∠B + ∠D=180°