Using the Pythagorean theorem:
a^2 + b^2 = c^2
a and b are the sides and c is the hypotenuse.
The length of the ladder would be the hypotenuse and the base away from the wall would be one side.
So now we have:
5.5^2 + b^2 = 9^2
Simplify:
30.25 + b^2 = 81
Subtract 30.25 from each side:
b^2 = 81 - 30.25
b^2 = 50.75
Take the square root of both sides:
b = √50.75
b = 7.123
Rounded to the nearest tenth of a foot = 7.1 feet.
