Irregular Hip Roof Geometry and Trigonometry
Proofs of General Plan Angle Formula

Corner Angle measured between Eaves in Plan View = 90°
Corner Angle measured between Eaves in Plan View > 90° ... Equal Roof Slope Angles and Plan Angles
Corner Angle measured between Eaves in Plan View > 90° ... Major Plan Angle < 90°
Corner Angle measured between Eaves in Plan View > 90° ... Major Plan Angle = 90°
Corner Angle measured between Eaves in Plan View > 90° ... Major Plan Angle > 90°

Joe Bartok