For the cyclic quadrilateral ABCD, which statement is true? A) The sum measure of ∠A and ∠B equals 180°. B) The sum measure of ∠A and ∠D equals 180°. C) The sum measure of ∠B and ∠D equals 180°. D) The sum measure of ∠C and ∠D equals 180°.
see the picture attached to better understand the problem
we know that A quadrilateral is called Cyclic quadrilateral if its all vertices lie on the circle. The opposite angles of a Cyclic - quadrilateral are supplementary so ∠A+∠C=180° and ∠B+∠D=180°
therefore the answer is C) The sum measure of ∠B and ∠D equals 180°
