9514 1404 393
Answer:
x = 10√3
Explanation:
The Pythagorean theorem tells you ...
FB^2 = BC^2 +CF^2
FA^2 = FB^2 +BA^2
Substituting for FB^2, we have ...
FA^2 = BC^2 +CF^2 +BA^2 = x^2 +x^2 +x^2
FA^2 = 3x^2
FA = x√3 = 30 . . . . take the square root and substitute for FA
x = 30/√3
x = 10√3