Question

Quadrilateral ABCD is cyclic , if m∠ B = 100°, find m ∠ D.
(A) 100°
(B) 260°
(C) 80°
(D) 180°​

Answer 1

Answer: (C) 80

Step-by-step explanation: Because, In a cyclic quadrilateral the sum of opposite angles = 180°

⇒∠A+∠C=180°

⇒∠B+∠D=180°

⇒ 100° + ∠D = 180°

⇒ ∠D = 180 - 100

⇒ ∠D = 80°