Answer:
Explanation:
21 is the side opposite the angle you want.
67 is the hypotenuse. Those two sides define the Sin
Sin(theta) = opposite / hypotenuse
Sin(theta) = 21 / 67
Sin(theta) = .313432
theta or x = sin-1(0.313432)
x = 18.27
Sorry, I must have hit the wrong key the first time.