Proposed Problem 381.
Quadrilateral, Diagonals, Angle Bisectors, Semi-sum of Angles.

Proposed Problem 382.
Concave Quadrilateral, Angle Bisectors, Semi-sum of Angles.

Proposed Problem 383.
Concave Quadrilateral, Angle Bisectors, Semi-difference of Angles.

Proposed Problem 384.
Triangle, Angle bisector, Perpendicular, Parallel, Semiperimeter.

Proposed Problem 385.
Triangle, Angle bisector, Perpendicular, Parallel, Semiperimeter.

Proposed Problem 386.
Triangle, Angle bisector, Perpendicular, Parallel, Semiperimeter, Congruence.

Proposed Problem 387.
Triangle, Angle bisector, Perpendicular, Concyclic points.

Proposed Problem 388.
Triangle, Angle bisector, Perpendicular, Parallel.

Proposed Problem 389.
Triangle, Parallel lines, Harmonic Mean.

Proposed Problem 390.
Triangle, Parallel lines, Collinear points.