Final answer:
The femur, or thigh bone, articulates with the coxa at the acetabulum to form the hip joint.
Step-by-step explanation:
The bone that articulates with the coxa at the acetabulum is the femur. The femur, also known as the thigh bone, is the longest, heaviest, and strongest bone in the human body. It forms the hip joint with the pelvis at its proximal end, where the rounded head of the femur fits into the acetabulum of the hip bone.
The acetabulum is a part of the hip bone that is comprised of contributions from the ilium, pubis, and ischium, which come together to form a socket that houses the head of the femur. This ball-and-socket joint provides a wide range of motion to the leg and supports the weight of the body.