Hope you are having a great day!
STEP BY STEP: a+b(x)=6
We have to use Pythagorean theorem that says :

The missing length of the triangle is : 36 feet
you have to use intercept theorem, also known as Thales's theorem to slove this problem
Answer:
18÷2 × 3 / 5-2
9 ×3 / 3
27/3
9
tyvm this was my 100th answer :)