Answer:
C. 30
Step-by-step explanation:
2x = 60
x = 30
Also because the right angle of a triangle which is the angle where (2x) is at is equal to 90 degrees always, so since one of the angles is 60 the other will be 30 because the three angles of a triangle add up to 180 degrees:
90 + 60 = 150
180 - 150 = 30
