Given:
Arc(AB) = 78 degrees
Measure of angle CMD = 106 degrees
To find:
The measure of arc CD.
Solution:
Secant intersection theorem: If two secant of a circle intersect each other inside the circle, then the intersection angle is the average of intercepted arcs.
Using secant intersection theorem, we get
Multiply both sides by 2.
Therefore, the measure of arc CD is 134 degrees and the correct option is C.