Answer:
I would use Euclid's first axiom:
Step-by-step explanation:
Things that are equal to the same thing are equal to each other.
Answer: Length of side QR is 16 units.
Step-by-step explanation: Given that dimensions of PQR
QPR= 90degrees
42-36=6
42+6=48
545.28 / 48=11.36
11.36
i'm pretty sure the one you have selected in the photo is right