Suppose the four angles of the quadrilateral are 3x, 5x, 9x and 13x.
∴ 3x + 5x + 9x + 13x = 360°
(by angle sum property of a quadrilateral)
⇒ 30x = 360°
⇒ x = 12°
Therefore, angles of the quadrilateral are 3 x 12°, 5 x 12°, 9 x 12° and 13 x 12°
i.e., 36°, 60°, 108° and 156°.
