Answer:
116°
Step-by-step explanation:
In a triangle, the sum of all interior angles is 180°
<PRS + <RSP + <SPR = 180°
51° + <RSP + 65° = 180°
<RSP = 180° - 65° - 51° = 180° - 116° = 64°
Since, <PST and <RSP are supplementary angles,
<PST + <RSP = 180°
<PST = 180° - 64° = 116°
