Answer:
We can use the Pythagorean theorem to solve this problem. Let's draw a diagram:
N
|\
| \
8 | \ x
| \
| \
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6 A
We know that Alex's house (A) is due west of Lexington, and due south of Norwood (N). We also know that the distance from Lexington to Alex's house is 6 miles, and the distance from Norwood to Lexington is 8 miles. We want to find the distance from Norwood to Alex's house, which we'll call x.
Using the Pythagorean theorem, we know that:
x^2 = 6^2 + 8^2
x^2 = 36 + 64
x^2 = 100
x = 10
Therefore, Norwood is 10 miles from Alex's house, measured in a straight line.