Information: - Mathematics (from Greek "mathma", knowledge, study, learning) is the study of topics such as quantity (numbers), structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope and definition of mathematics. - Geometry (from the ; "geo-" "earth", "-metron" "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. A mathematician who works in the field of geometry is called a geometer. - In geometry , the ( angular ) defect ( or deficit or deficiency ) means the failure of some angles to add up to the expected amount of 360 or 180 , when such angles in the plane would . The opposite notion is the excess . Classically the defect arises in two ways : the defect of a vertex of a polyhedron ; the defect of a hyperbolic triangle ; and the excess also arises in two ways : the excess of a toroidal polyhedron . the excess of a spherical triangle ; In the plane , angles about a point add up to 360 , while interior angles in a triangle add up to 180 ( equivalently , exterior angles add up to 360 ) . However , on a convex polyhedron the angles at a vertex on average add up to less than 360 , on a spherical triangle the interior angles always add up to more than 180 ( the exterior angles add up to less than 360 ) , and the angles in a hyperbolic triangle always add up to less than 180 ( the exterior angles add up to more than 360 ) . In modern terms , the defect at a vertex or over a triangle ( with a minus ) is precisely the curvature at that point or the total ( integrated ) over the triangle , as established by the Gauss -- Bonnet theorem . - Space is the boundless three-dimensional extent in which objects and events have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime. The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework. Given the information above, choose from the list below the object entity that exhibits the relation 'subclass of' with the subject 'angular defect'. Choices: - change - direction - field - geometry - greek - mathematician - mathematics - measurement - part - position - quantity - shape - space - study
quantity