Answer:
20 miles.
Step-by-step explanation:
You're on the right track with your answer of 12. You added the sides you knew & multiplied by 2.
I'm picturing the park like a rectangle. So there are two sides that are 3 miles long, and 2 sides that are 2 miles long. For perimeter, we add all the sides.
3 + 3 + 2 + 2 = 10. And he walked the park twice, so 2 x 10 = 20
