Answer:
Let O is intersection of RS and TU
As property of angle on circle:
angle OSU = angle RSU = (1/2) arc RU = (1/2) x 70 = 35
angle OUS = angle TUS = (1/2) arc TS = (1/2) x 86 = 43
=> As sum of all angles inside triangle UOS is equal to 180
=> UOS = 180 - OSU - OUS = 180 - 35 -43 = 102 deg
Hope this helps!
:)