Answer: 92° or 1.6057 radians
Explanation:
the 4 angles created by the intersecting lines SU and RT have to equal 360°
<v = 88° because of vertical angles so
88° • 2 = 176°
360° - 176° = 184°
184°/ 2 = 92°
92°+92°+88°+88° = 360°
then, that makes 92° the central angle of arc RU and the central angle degrees is always equal to the arc it subtends
hope this helps :)