9514 1404 393
Answer:
B. x = 2√11
Explanation:
The square of the length of the diagonal is ...
d² = 6² + 8² = 36 +64 = 100
Then the length of x is found from ...
d² +x² = 12²
x² = 144 -100 = 44 . . . . . subtract d²
x = √44 . . . . . . take the square root
x = 2√11