Answer: minimum length ladder that a worker needs to access a landing nine feet above the adjacent floor is 12 feet
So with the standard terms the ladder should be at least 1 unit away for 4 feet of height so, keeping in mind the unitary method:
Height Away from base
4 1
9 x
Cross multiply:
x = 9/4
x = 2.5 feet away from the base
Using the Pythagoras Theorem:
a² + b² = c²
place the values (a = 2.5, b = 9):
2.5² + 9² = c²
= 9.34 feet
Now, the length should always be more than the height:
9.34 + 2 = 11.34
A minimum of 11.34 feet. As a result, rounding off would result in a 12 foot ladder.