Answer:
13.7 inches
Step-by-step explanation
Area = base*height
(since it's a square, the lengths of all four sides of the board are equal. therefore, we can write the equation above like the following)
Area of square = side length^2
(square root both sides of the equation, and you get the following)
= side length
(now, substitute the info)
= x
(solve)
x = 13.7 inches