Answer:
<2 = 78°
Explanation:
Observations first!
1 and 3 are corresponding angles.
2 and 4 are corresponding angles also.
So we can say that <1 = <3(angle 1 equals angle 3)
And also <2 = <4(angle 2 equals angle 4)
If this is true...
<1 and <2 make a supplementary angle.
<3 and <4 make a supplementary angle.
Then this is too...
<1 and <4 make a supplementary angle.
<2 and <3 make a supplementary angle.
Then lets equal angle 2 and 3 to 180 to find the value of x.
Note: Some people might equal them together but that wouldn't be correct because they are not the same angle.
18x + 6 + 21x + 18 = 180
39x + 24 = 180
39x = 156
x = 4
The last thing is to plug in x in the angle's 2 value.
18(4) + 6 = 72 + 6 = 78
Check your work!
You can find <3 value the same way we did for <2, then make sure both angles add up to 180 (work shown below).
21(4) + 18 = 84 + 18 = 102
102 + 78 = 180