Question

The three successive angles of a cyclic quadrilateral are in the ratio 1:3:4, find
the measure of the fourth angle?

Answer 1

Answer:

Sum of the opposite angles in cyclic quadrilateral is 180°

∠A + ∠C = 180°

⇒ x + 4x = 180°

∴ x = 36°

Now ∠B = 3x = 3 × 36° = 108°

∠D = 180 - ∠B = 180 - 108 = 72°