There are infinite values of y possible. Take you pick.
1,2,3 and 4 are as good as any.
Answer: 12.20 feet.
Step-by-step explanation:
Observe in the figure attached that a right triangle is formed.
Then, you need to remember the identity:
In this case you can identify that:
Then, to find the length of the wooden board (x), you need to substitute values and solve for x.
Therefore, you get:
The length of the wooden board is: 12.20 feet.