Answer:
Angle 1 is 140.
Explanation:
Set angle 1 and angle 3 equal to each other since they are congruent to each other to get this equation 20x+60=30x+20. Subtract 20x on both sides to get this equation 60 = 10x + 20. Subtract 20 on both sides to get to 40 = 10x. Divide 10 on both sides to get your x-variable which is 4. Since you are solving for angle 1, plug in the x-value to get 20(4)+60. You should get 140 degrees as your final answer.