Answer:
x is equal to 50.
Step-by-step explanation:
The three lines intersect creating a triangle. All angle measures for triangles in Euclidean geometry must have a sum of 180 degrees. Because of the Vertical angles theorem, which states if two angles are opposite they are congruent, this means the angle across from 40 degrees is also 40 degrees. Since we know that the second angle is 90 degrees based on the right angle sign. By adding 40 and 90 you get a sum of 130. Now you subtract 130 from 180. This gives you 50 degrees. Since the Vertical angle theorem states two opposite angles are congruent we know the x is equal to 50 degrees.