Height of fence = 10 feet
Height of point where window needs to be washed = 14 feet
Distance between fence and building = 2 feet
Distance between fence and ladder = 10 feet
⇒ Distance between building and ladder = Distance between fence and building + Distance between fence and ladder
⇒ Distance between building and ladder = 2 + 10 feet
⇒ Distance between building and ladder = 12 feet
Now to determine the length of the ladder that goes over the fence, we can use the Pythagoras theorem, where perpendicular is represented by the height of the building, and base is represented by distance between the building and the ladder, and the length of the ladder represents the hypotenuse
So by Pythagoras theorem:
H² = P² + B²
⇒ Length of the Ladder² = Height of the Building² + Distance between Ladder and Building²
⇒ Length of the Ladder² = 14² + 12²
⇒ Length of the Ladder² = 196 + 144
⇒ Length of the Ladder² = 340
⇒ Length of the Ladder = √340
⇒ Length of the Ladder = 18.439..
⇒ Length of the Ladder = 18.4
Hence, the length of the ladder should be 18.4 feet
