Physics PLEASE HELP
posted by Kayla .
A painter climbs a ladder leaning against a smooth wall. At a certain height, the ladder is on the verge of slipping. Let the mass of the painter be 69.0 kg, length = 2.80 m, the ladder’s mass to be 21.0 kg, θ = 57.0°, and the coefficient of friction between ground and ladder be 0.290. (a) What is the lever arm for the horizontal force of the wall on the ladder with the axis of rotation taken at the base of the ladder? (The lever arm is the perpedicular distance between the base of the ladder and the force exerted by the wall.)

L•sinθ