What is the proper slant for a portable straight ladder?

The correct answer is based on the recommended angle for setting up a portable straight ladder for safe use. The proper slant for a ladder is typically established using the 4-to-1 rule, which states that for every 4 feet of vertical height, the base of the ladder should be 1 foot away from the wall or structure it is leaning against. This angle ensures stability and reduces the risk of the ladder slipping or tipping over.

In the context of the options, the ratio described in choice B, where there is a 12-foot vertical height paired with a 3-foot horizontal distance, translates to a similar ratio of 4-to-1. This means that for every 4 feet of height, the ladder is placed 1 foot away from the wall. Therefore, with a vertical height of 12 feet, the corresponding horizontal distance of 3 feet is appropriate for maintaining a safe angle.

When setting up a ladder, ensuring this correct slant is crucial to prevent accidents, as a ladder set at an improper angle can lead to falls or instability. Understanding and applying the 4-to-1 rule when positioning a ladder is an essential aspect of ladder safety.