A hip rafter is a roof framing member that travels from the ridge to an "outside" corner of the roof. It does so in one complete, unbroken member. When a hip intersects a corner of any angle in half, it creates two "equal" angles on either side of the hip. This is then called a regular hip rafter. In all most every case the hip will intresect a 90° corner and divide it into two 45° angles.