Answer:
45 degrees
Explanation:
Since we have a right triangle, we use the appropriate trigonometric ratio
The angle marked P faces QR and that makes it the opposite side
PR faces the right angle and that makes it the hypotenuse
The trigonometric ratio that links the opposite and the hypotenuse is the sine
It is the ratio of the opposite to the hypotenuse
Thus;
sin P = √26/2 √13
Sin P = √2/2
P = arc sin √2/2
P = 45 degrees