What is the minimum distance between the foot of a ladder and the base of the structure it's leaning against?

• A. 1/8 of the vertical distance
• B. 1/4 of the vertical distance
• C. 1/2 of the vertical distance
• D. Equal to the vertical distance

Answer: (B)

Ladder safety hinges on the angle it makes with the wall. The ladder, wall, and floor form a right triangle, and a safe, recommended angle is about 75–76 degrees. At that angle, the base distance from the wall is roughly one-quarter of the vertical height the ladder reaches. That is why the minimum distance is h/4, where h is the vertical distance. If you move the base closer, the angle becomes steeper and stability can decrease; if you move it farther, the angle becomes too shallow and the ladder can slip outward. So the safe minimum distance corresponds to one-quarter of the vertical distance the ladder reaches.