A 13m long ladder leans against a wall in a Delhi apartment. If its foot is 5m from the wall, the angle it makes with the ground is:

A 13m long ladder leans against a wall in a Delhi apartment. If its foot is 5m from the wall, the angle it makes with the ground is:

• A. sin⁻¹(5/13)
• B. cos⁻¹(5/13)
• C. tan⁻¹(5/13)
• D. cot⁻¹(5/13)

Answer: B) cos⁻¹(5/13)

Explanation: The ladder is the hypotenuse (13m) and the base is 5m. cos(θ) = base / hypotenuse = 5/13. Hence θ = cos⁻¹(5/13).