Q: Information: - A triangular number or triangle number counts the objects that can form an equilateral triangle, as in the diagram on the right. The th triangular number is the number of dots composing a triangle with dots on a side, and is equal to the sum of the natural numbers from 1 to . The sequence of triangular numbers , starting at the 0th triangular number, is - 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, an octagon (from the Greek "oktagnon", "eight angles") is an eight-sided polygon or 8-gon. - In mathematics, a polygonal number is a number represented as dots or pebbles arranged in the shape of a regular polygon. The dots are thought of as alphas (units). These are one type of 2-dimensional figurate numbers. - In planar geometry, an angle is the figure formed by two rays, called the "sides" of the angle, sharing a common endpoint, called the "vertex" of the angle. Angles formed by two rays lie in a plane, but this plane does not have to be a Euclidean plane. Angles are also formed by the intersection of two planes in Euclidean and other spaces. These are called dihedral angles. Angles formed by the intersection of two curves in a plane are defined as the angle determined by the tangent rays at the point of intersection. Similar statements hold in space, for example, the spherical angle formed by two great circles on a sphere is the dihedral angle between the planes determined by the great circles. - An octagonal number is a figurate number that represents an octagon . The octagonal number for n is given by the formula 3n2 - 2n , with n > 0 . The first few octagonal numbers are : 1 , 8 , 21 , 40 , 65 , 96 , 133 , 176 , 225 , 280 , 341 , 408 , 481 , 560 , 645 , 736 , 833 , 936 ( sequence A000567 in OEIS ) Octagonal numbers can be formed by placing triangular numbers on the four sides of a square . To put it algebraically , the n - th octagonal number is x_n = n ^ 2 + 4 \ sum -- ( k = 1 ) ^ ( n - 1 ) k = 3n ^ 2 - 2n . The octagonal number for n can also be calculated by adding the square of n to twice the ( n - 1 ) th pronic number . Octagonal numbers consistently alternate parity . Octagonal numbers are occasionally referred to as '' star numbers , '' though that term is more commonly used to refer to centered dodecagonal numbers . - The term figurate number is used by different writers for members of different sets of numbers, generalizing from triangular numbers to different shapes (polygonal numbers) and different dimensions (polyhedral numbers). The term can mean - The Multinational Aircrew Electronic Warfare Tactics Facility Polygone - POLYGON is an Electronic Warfare Tactics Range located on the border between Germany and France. It is a tri-national facility operated by France, Germany and the United States. Given the information above, choose from the list below the object entity that exhibits the relation 'subclass of' with the subject 'octagonal number'. Choices: - angle - diagram - facility - geometry - germany - greek - intersection - mathematics - measurement - natural - number - octagon - plane - polygonal number - range - regular polygon - sequence - shape - sum - term - type - warfare
A: polygonal number

Q: Information: - Shadows of Forgotten Ancestors ( Ukrainian : , Tini zabutykh predkiv ) , also called Shadows of Our Forgotten Ancestors , Shadows of Our Ancestors , or Wild Horses of Fire -- is a 1965 film by the Soviet filmmaker Sergei Parajanov based on the classic book by Ukrainian writer Mykhailo Kotsiubynsky . The film was Parajanov 's first major work and earned him international acclaim for its rich use of costume and color . The film also features a detailed portrayal of Ukrainian Hutsul culture , showing not only the harsh Carpathian environment and brutal family rivalries , but also the beauty of Hutsul traditions , music , costumes , and dialect . - Sergei Parajanov ( sometimes spelled Paradzhanov or Paradjanov; January 9, 1924 July 20, 1990) was a Soviet film director and artist of Armenian descent who made significant contributions to Soviet cinematography through Ukrainian, Armenian, and Georgian cinema. He invented his own cinematic style, which was totally out of step with the guiding principles of socialist realism (the only sanctioned art style in the USSR). This, combined with his controversial lifestyle and behaviour, led Soviet authorities to repeatedly persecute and imprison him, and suppress his films. - Armenia ( tr. "Hayastan"), officially the Republic of Armenia (tr. "Hayastani Hanrapetutyun"), is a sovereign state in the South Caucasus region of Eurasia. Located in Western Asia on the "Armenian Highlands", it is bordered by Turkey to the west, Russia and Georgia to the north and Azerbaijan to the east, and Iran and Azerbaijan's exclave of Nakhchivan to the south. - Socialist realism is a style of realistic art that was developed in the Soviet Union and became a dominant style in that country as well as in other socialist countries. Socialist realism is characterized by the glorified depiction of communist values, such as the emancipation of the proletariat, by means of realistic imagery. Although related, it should not be confused with social realism, a type of art that realistically depicts subjects of social concern. - A film director is a person who directs the making of a film. Generally, a film director controls a film's artistic and dramatic aspects, and visualizes the script while guiding the technical crew and actors in the fulfillment of that vision. The director has a key role in choosing the cast members, production design, and the creative aspects of filmmaking. Under European Union law, the director is viewed as the author of the film. Given the information above, choose from the list below the object entity that exhibits the relation 'country of origin' with the subject 'shadows of forgotten ancestors'. Choices: - armenia - european union - iran - russia - soviet union - turkey
A: soviet union