Take into account that for secant and tangent lines related to circles, use the following formula:
x = 1/2·(larger arc - smaller arc)
Then, you have, for the first circle:
larger arc = 360° - 124° = 236°
smaller arc = 124°
x = 1/2·(236° - 124°)
x = 1/2·(112°)
x = 56°
For the second circle, the value of x is the same that the given arc:
x = 124°
For the fourth circle:
larger arc = 171°
smaler arc = 67°
x = 1/2·(171° - 67°)
x = 1/2·(104°)
x = 52°
For the fifth circle:
x = 1/2·(101° + 39°)
x = 70°
