Answer:
x = 50°
d = 40°
Explanation:
Angle sum property of quadrilateral:
Quadrilaterals are four-sided polygon and the sum of all the interior angles is 360°
Sum of all angles of quadrilateral = 360°
60° + x + 3x + 2x = 360
60 + 6x = 360
Subtract 60 from both sides,
6x = 360 - 60
6x = 300
Divide both sides by 6
x = 300 ÷ 6
x = 50°
b) 120° + 110° + 90° + d= 360°
320 + d = 360
Subtract 320 from both sides,
d = 360 - 320
d = 40°