For each of the problems, twice the angle formed by the chords is equal to half the sum of the angles of the arcs.
So, for the first problem, we have

, so

.
For the second,

, so

.
For the last problem,

, so

.
Feel free to comment below if you have any questions!
Answer:
C)infinitely many solutions
Step-by-step explanation:

Write that as 7x. Writing it as x7 could lead to confusion. 7*x would be OK.