Part a:
The diameter of a circle bisects two intersecting tangents.
In the given diagram, OU is the diameter of the circle and SU and VU are tangents to the circle.
Angle SUT = TUV. Since angle SUT is 39, angle TUV = 39.
The arc measure that describes arc VTS is mVS
Part b
Knowledge of the radius length helps in the calculation of the line segments MT, MO, OT and NS.
Part c
If angle MOP = 49, then angle QTR can be calculated as 90 - 49 = 41. Also, angle MQR is calculated as 180 - 49 = 131