What is the correct safe working angle for a ladder when positioned?

The correct safe working angle for a ladder is typically represented by a ratio indicating how far the base of the ladder should be positioned from the vertical surface compared to the height it reaches. A ratio of 1/4 from the vertical surface signifies that for every four units of height, the base of the ladder should be one unit away from the wall. This 1:4 ratio is considered safe as it helps to ensure that the ladder maintains stability and reduces the risk of it slipping or tipping over while in use.

When a ladder is placed at this angle, it allows users to work safely at height, as the ladder's center of gravity is maintained closer to the vertical plane, providing adequate support. While other ratios, such as the ones suggesting it be positioned closer or further away from the vertical surface, might seem plausible, they do not provide the same level of safety and stability recommended for ladder use. The 1/4 ratio is widely adopted in safety guidelines for ladder usage across various industries, reinforcing its correctness.