Non-self-supporting ladders should be placed at an angle where the horizontal distance from the top support to the foot equals what fraction of the ladder's working length?

Non-self-supporting ladders should be placed at an angle where the horizontal distance from the top support to the foot equals what fraction of the ladder's working length?

• A. 1/4
• B. 1/2
• C. 1/3
• D. 1/6

Answer: (A)

Non-self-supporting ladders are safest when they lean at a specific angle that balances reach with stability. The standard rule is the 4-to-1 setup: for every four units of height up the ladder, place one unit of horizontal distance from the wall. In other words, the horizontal distance from the top support to the foot should be one-quarter of the ladder’s working length. Geometrically, if the ladder length is L, the base distance is L/4, which gives a lean angle of about 75 degrees—a sturdy, stable position. If the base distance is too large, the ladder sits too shallow and the top can slip; if it’s too small, the ladder sits too vertical and can tip or press hard against the wall. Among the given options, one-quarter of the working length is the safe, recommended fraction.

Non-self-supporting ladders are safest when they lean at a specific angle that balances reach with stability. The standard rule is the 4-to-1 setup: for every four units of height up the ladder, place one unit of horizontal distance from the wall. In other words, the horizontal distance from the top support to the foot should be one-quarter of the ladder’s working length. Geometrically, if the ladder length is L, the base distance is L/4, which gives a lean angle of about 75 degrees—a sturdy, stable position. If the base distance is too large, the ladder sits too shallow and the top can slip; if it’s too small, the ladder sits too vertical and can tip or press hard against the wall. Among the given options, one-quarter of the working length is the safe, recommended fraction.