To isolate an enclosed area for conservation, an open traverse is run keeping close to (but outside of) the exterior boundary of the area through ground points   towards  (to be eventually located).  is 80^o to the East of the East of the North line at  Deflection/Interior angles at  are indicated. What would be the magnitude of the deflection angle at  (as marked) so that  many run parallel to ? (Lengths are immaterial in this case.)