As the triangles are similar, their corresponding sides are in the same ratio.
Here, vertex
A corresponds to vertex
P.
Given:
AB=6 ft,BC=10 ft,AC=12 ft, and
PQ=3.6 ft.
So,
ABPQ=BCQR=ACPR
⇒ 63.6=10QR=12PR
⇒ QR=6 ft
And
PR=92.5=7.2 ft
So,
QR+PR=6+7.2=13.2 ft