The answer you’re looking for is x=145.
Every circle adds up to 360 degrees. The only measurement that we know is 70, but the congruent markings tell us that the unknown “sides” are the same. Therefore, you’d take 360-70=290. There are 290 degrees around the unknown part of the circle, which we then divide by 2 to get 145 degrees total. I hope this helped, let me know if I can explain anymore:)
