Answer:
9.2 ft
Explanation:
The shape is a triangle, the 11 ft is your hypotenuse 
You need to use the Pythagorean Theorem! 
a^2 + b^2 = c^2 (solve for a, the missing length that they ask for)
so --->
a^2 + (6^2) = 11^2
 a^2 + 36 = 121
 ~subtract 36 to the right side~
 a^2 = 85
now find the square root of 85:
 a = 9.21954
 round it to the nearest tenth:
 a = 9.2
final answer: 9.2 ft
hope this helpsss