High Quality Content by WIKIPEDIA articles! In geometry, a spherical wedge or ungula is a portion of a ball bounded by two plane semidisks and a spherical lune (termed the wedge's base). The angle between the radii lying within the bounding semidisks is the dihedral angle of the wedge ?. If AB is a semidisk that forms a ball when completely revolved about the z-axis, revolving AB only through a given ? produces a spherical wedge of the same angle ?. Beman (2008) remarks that "a spherical wedge is to the sphere of which it is a part as the angle of the wedge is to a perigon."[A] A spherical wedge of ? = ? radians (180°) is called a hemisphere, while a spherical wedge of ? = 2? radians (360°) constitutes a complete ball. The volume of a spherical wedge can be intuitively related to the AB definition in that while the volume of a ball of radius r is given by tfrac{4}{3} pi r^3, the volume a spherical wedge of the same radius r is given by frac{alpha}{2pi} cdot frac{4}{3} pi r^3 = frac{2}{3} alpha r^3

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.