we know that
The measure of the interior angle is the half-summit of the arcs that comprise it and its opposite.
∡PRM=(1/2)*[mPM+mQN]
mQN=163.5°
mPM=360-[163.5+72+78]-----> mPM=46.5°
∡PRM=(1/2)*[46.5+163.5]-----> 105 °
the answer is
∡PRM is 105 degrees