Help how do I do it?
A
B
C
D

C
x = 50
If the two angles add up to 140 then that means 40° + 2x° equals 140
Set up an equation from that evaluation and solve
40 + 2x = 140
Subtract 40 from both sides
2x = 100
Divide both sides by two
x = 50
Hope this helps.