What are the bones that make up the hips, lower spine, and tailbone?

Hips are the: proximal femur and femur head articulating with the acetabulum. A lot of people regard the lower back area on the sides as hips -- which is instead is the sacroiliac joint region -- which involves the sacrum and the ilium. The lower spine involves the lumbar vertebrae, and the tailbone which is located right over the anus is the coccyx. Hope this helps.