Circle P has secants SU and TQ as shown. What is the measure of angle R?
Since angle(R) is exterior to the circle it will be the difference of the two intercepted arcs divided by 2.
angle(R) = ( arc(SQ) - arc(TU) ) / 2 = ( 103 - 43 ) / 2 = 60 / 2 = 30.
