Answer: sqrt(72) or 8.49 rounded.
Step-by-step explanation: This can be solved by realizing that diagonal makes an isosceles triangle with the sides so we use the pythagorean theorem to solve. X^2 + X^2 = 144 or rewritten
2X^2 = 144 divide by 2
X^2 = 72 square root
X = sqrt(72) = 8.49 (rounded to 2 decimals)
