Answer:
15 feet
Explanation:
So, to start we have to find the area of the wall.
9(12)=108
Now, we need to find half of the walls area
108/2=54
We have our length and height, but we need to find the hypotenuse using Pythagoreans theorem.
9 is our A and 12 is our B
a^2+b^2=c^2
81+144=c^2
c^2=225
The square root of 225 is 15.
C=15
Therefore, the stripe will be 15 feet.