Answer:
x = 110°
Explanation:
∠ QRS = ∠ YRT = 110° ( vertically opposite angles )
∠ PQR = 180° - 120° = 60° ( adjacent angles )
The sum of the interior angles of a quadrilateral = 360°
Sum the angles and equate to 360°, that is
110 + 60 + x + 80 = 360
250° + x = 360° ( subtract 250° from both sides )
x = 110°