Answer:
[tex]m\angle 1 = 40^\circ[/tex]
Step-by-step explanation:
First, notice that the two lines are parallel as indicated by the arrow.
Therefore, by the Alternate Interior Angles Theorem:
[tex]\angle 1\cong \angle 2[/tex]
So:
[tex]m\angle 1 = m\angle 2[/tex]
Substitute:
[tex](2x+20)=(3x+10)[/tex]
Solve for x. Subtract 2x from both sides:
[tex]20=x+10[/tex]
And subtract 10 from both sides:
[tex]x=10[/tex]
We know that:
[tex]m\angle 1 = 2x+20[/tex]
Substitute. Hence:
[tex]m\angle 1 =2(10)+20=40^\circ[/tex]
