9514 1404 393
Answer:
10.4
Explanation:
The Pythagorean theorem applies to the sides of this right triangle.
x² + 6² = 12²
x² +36 = 144 . . . . find the squares
x² = 108 . . . . . . . . subtract 36
x = √108 . . . . . . . take the square root
x ≈ 10.4