Answer:
PR = 34
Explanation:
The diagonals of a square bisect each other, and are congruent, thus
QS = PR, that is
7x - 8 = x + 11 + x + 11 = 2x + 22 ( subtract 2x from both sides )
5x - 8 = 22 ( add 8 to both sides )
5x = 30 ( divide both sides by 5 )
x = 6
Thus
PR = 2x + 22 = 2(6) + 22 = 12 + 22 = 34