Concave polygon Concave polygon A simple polygon that is not convex is called concave, non-convex or reentrant. A concave polygon will always have at least one reflex interior angle—that is, an angle with a measure that is between 180 degrees and 360 degrees exclusive. Some lines containing interior points of a concave polygon intersect its boundary at more than two points. Some diagonals of a concave polygon lie partly or wholly outside the polygon. Some sidelines of a concave polygon fail to divide the plane into two half-planes one of which entirely contains the polygon. None of these three statements holds for
Allied Masonic Degrees with the presiding officer being denominated 'Sovereign Master." The Councils are given wide discretion as to choose how frequently they meet and what programs to pursue. Generally speaking, Councils study or discuss Freemasonry in some way at each meeting. The Grand Council has created some internal honors, the most notable being "Knight Grand Cross". The degrees conferred in the United States are: In Canada, the degrees conferred are: Optional degrees are: Royal Order of the Red Branch of Eri: "Fun" degrees: (given at the Annual Assembly) Allied Masonic Degrees The Allied Masonic Degrees (AMD) are a series of Masonic degrees