What bone articulates (joints) with the acetabulum of the coxal bone?

The head of the femur articulates with the acetabulum of the hip bone.

The acetabulum is a deep rounded depression on the outer surface of the coxa/hip bone. Into this depression fits the upper end or head of the femur, to form the hip joint. The femur is the long bone of the thigh. This joint is therefore the best example of a ball and socket type of joint.