Hi there!
In order to figure out the distance between A and B, we need to use pythagorean theorem. We need to find the A value, as we have the B and C values. Then, we solve for A to find the distance between A and B.
WORK:
a^2 + 6^2 = 9^2
a^2 + 36 = 81
a^2 = 45
a = 6.71 miles
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!