For a 20 ft. extension ladder leaning against a building, how far from the base of the building should the foot of the ladder be?

To determine the ideal distance for the base of the ladder from the wall, we can reference the common safety guideline which suggests that the base of the ladder should be placed one foot away from the wall for every four feet of ladder height.

In this scenario, the extension ladder is 20 feet long. According to the guideline:

1. For every 4 feet of height (which can be represented as the vertical side of a right triangle where the ladder forms the hypotenuse), the base should be 1 foot away from the wall.

2. This means we would calculate the distance as follows: 20 feet (height of the ladder) divided by 4 equals 5. This calculation tells us that the foot of the ladder should be 5 feet away from the building.

This ratio is critical for maintaining stability, ensuring that the ladder does not slip or tip over while in use. Therefore, placing the base of the ladder 5 feet from the wall is the safest and most effective position.