Answer:
x equals 10, angle measure is 30°
Step-by-step explanation:
By using the Vertical Angles Theorem which states that opposite angles formed by 2 intersecting lines are congruent we can find that the measure of the angle with 3x is equal to the measure of it's opposite angle or 30°. Using this we can make an equation that can find us our answer.
3x = 30
Divide both sides by 3
3x/3 = 30/3
x = 10
