In the diagram above

Answer:
140
Step-by-step explanation:
First you have to solve for x
20x + 60 = 30x + 20
so you would subtract 20x from both sides
60 = 10x + 20
then subtract 20 from both sides
40 = 10x
then divide both sides by 10
4 = x
then you would put 4 in for x in the equation for angle 1
20(4) + 60
80 + 60
140
Answer:
angle 1=20(4)+60=140 degrees
Step-by-step explanation:
theory : If two parallel lines are cut by a transversal, the corresponding angles are congruent.
so angle 1 and angle 3 are equal:
20x+60=30x+20
60-20=30x-20x
40=10x
x=40/10=4
angle 1 = 20(x)+60
angle 1=20(4)+60=140 degrees