What is the relation between the opposite angles of a cyclic quadrilateral?

ABCD is a cyclic quadrilateral. If ∠ADB = x° and ∠ABD = y° then ∠BCD is (x + y)°.

Write the magnitude of each angle of a cyclic parallelogram

BOC is a diameter of a circle whose centre is O. ABCD is a cyclic quadrilateral. If ∠ADC =110°, find ∠ACB

ABCD is a cyclic quadrilateral. Chord DE is the external bisector of ∠BDC. Prove that AE (or produced AE) is the external bisector of ∠BAC.

Prove that the opposite angles of a cyclic quadrilateral are supplementary.

Prove that in a cyclic quadrilateral opposite angles are supplementary.

Prove that a cyclic trapezium is an isosceles trapezium.

ABCD is a cyclic quadrilateral. Bisectors of ∠DAB and ∠BCD intersect the circle at X and Y respectively. If O be the centre of the circle, find ∠XOY.

Prove that in a cyclic quadrilateral opposite angle are supplementary.

AB and CD are two chords of a circle. If we extend BA and DC, they intersect each other at point P. Prove that ∠PCB = ∠PAD.

State True/False: “The equal chords of a circle are at equal distances from the centre of the circle.”