We can use the Pythagorean theorem to solve. (a² + b² = c²)
Fill in with what we know → 6² + b² = 11²
Simplify → 36 + b² = 121
Subtract 36 to both sides → 36 - 36 + b² = 121 - 36
Simplify → b² = 85
Take the root of both sides → √b² = √85
Simplify → b = 9.2195...
Round if necessary → 9.2195 = 9.22
Hence, b equals 9.2195.. (unrounded) or 9.22 (rounded).
Best of Luck!