45 POINTS PLEASE HELP! I WILL MARK BRAINLIEST!

The answer is definitely x=123.
if you plug in the value of x into the formula for finding secant-secant measurements, you get 123.
angle= 1/2 (big arc - small arc)
23= 1/2 (123 - 77)
23= 1/2 (46)
23=23
123 is the big arc value that you are solving for.