Answer: 60°
Step-by-step explanation:
(x+40) is opposite to (3x) so they are equal
so x+40 = 3x
now we can solve the equation,
subtract one x from each side so now it is 40=2x
then divide by 2 on each side so now 20=x
no plug in the x to (3x) so 3(20)
3(20) = 60
so teh angle is 60°