The shape of the U has lots of room to play with, from the width of the longest layers to the angles to the shorter layers. This is a wide U-shape with a steep diagonals to the shortest shoulder length layers. It creates a striking shape with this thick long hair and lets the shortest layers fall in front of the shoulders to hit the collarbone.
This long layered hairstyle features a deep U-shaped back, with a narrow rounded bottom and arced steep sides. This option is better for thinner hair than the wide U above.
The U-shaped back is also super flattering for curly and wavy hair. The different length layers create a gorgeous shape as bring out natural texture. These looks work with all lengths of hair, leaving layers to frame the face that are between chin and shoulder length.