The measure of angle P is 43°
Explanation:
If a quadrilateral is inscribed inside a circle, the sum of opposite angles is always equals 180 degrees.
The angle POR is opposite to the angle PQR, and the angle OPQ is opposite to the angle ORQ.
So we have that:
mOPQ + mORQ = 180°
y + 3y + 8 = 180
4y = 172
y = 43°
So the measure of angle P is 43°