Hopper angles are the same angles that are use for cutting roof sheathing. The hopper miter angle is the same as the jack rafter side cut angle and the hopper saw blade bevel angle is the same as the hip rafter backing angle.
Hopper Miter Angle = arctan (cos(Roof Pitch Angle) ÷ tan (Plan Angle))
Hopper Saw Blade Bevel Angle for Mitered Hopper = arctan( sin ( Hip Rafter Angle ) ÷ tan ( Plan Angle ))
Hopper Saw Blade Bevel Angle for Butt Joint Hopper = arctan( 90° - (sin ( Hip Rafter Angle ) ÷ tan ( Plan Angle )*2))
The hopper slope angle is measured from an horizontal plane.
12 sided polygon hopper table:
Hopper Slope angle = 78°
Corner angle = 150°
Miter Angle = 3.18864°
Bevel Angle = 14.66478°
See the complete process of laying out the hopper table at the link below. You should only view the link online with an Wifi connection.