Right angle of what a right angle is, namely two straight lines intersecting to form two equal and adjacent angles. The straight lines which form right angles are called perpendicular. Euclid uses right angles in definitions 11 and 12 to define acute angles (those smaller than a right angle) and obtuse angles (those greater than a right angle). Two angles are called complementary if their sum is a right angle. Book 1 Postulate 4 states that all right angles are equal, which allows Euclid to use a right angle as a unit to measure other angles with. Euclid's commentator Proclus gave a
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