What should the angle of a leaning ladder be to ensure safety?

The safest angle for a leaning ladder is indeed 75 degrees. This angle allows for optimal stability and minimizes the risk of the ladder slipping or tipping over. At this angle, the ladder is not too steep that it becomes difficult to climb nor is it too shallow, which could increase the likelihood of it sliding outwards from the wall it leans against.

When setting up a ladder, the 75-degree angle is recommended because it aligns well with the body's center of gravity, providing balance and promoting safe use. Climbing at this angle reduces the strain on the user and enhances overall safety by ensuring that the ladder maintains contact with the ground and the surface it rests against.

While 60 degrees may be safe for other climbing situations, it does not offer the same level of security as 75 degrees, making it less ideal for ladder use. A 90-degree angle is vertical and not safe for a leaning ladder, as it would be unstable and potentially cause falls. A 45-degree angle, while sometimes seen in certain scenarios, is too shallow for optimal safety when using a ladder.