The Schläfli symbol of the hexadecachoron is {3,3,4}. Its vertex figure is a regular octahedron. There are 8 tetrahedra, 12 triangles, and 6 edges meeting at every vertex. Its edge figure is a square. There are 4 tetrahedra and 4 triangles meeting at every edge.
There is a lower symmetry form of the "16-cell", called a demitesseract or 4-demicube, a member of the demihypercube family, and represented by h{4,3,3}, and can be drawn bicolored with alternating tetrahedral cells.
One can tessellate 4-dimensional Euclidean space by regular 16-cells. This is called the hexadecachoric honeycomb and has Schläfli symbol {3,3,4,3}. The dual tessellation, icositetrachoric honeycomb, {3,4,3,3}, is made of by regular 24-cells. Together with the tesseractic honeycomb {4,3,3,4}, these are the only three regular tessellations of R. Each 16-cell has 16 neighbors with which it shares an octahedron, 24 neighbors with which it shares only an edge, and 72 neighbors with which it shares only a single point. Twenty-four 16-cells meet at any given vertex in this tessellation.
The cell-first parallel projection of the 16-cell into 3-space has a cubical envelope. The closest and farthest cells are projected to inscribed tetrahedra within the cube, corresponding with the two possible ways to inscribe a regular tetrahedron in a cube. Surrounding each of these tetrahedra are 4 other (non-regular) tetrahedral volumes that are the images of the 4 surrounding tetrahedral cells, filling up the space between the inscribed tetrahedron and the cube. The remaining 6 cells are projected onto the square faces of the cube. In this projection of the 16-cell, all its edges lie on the faces of the cubical envelope.
The cell-first perspective projection of the 16-cell into 3-space has a triakis tetrahedral envelope. The layout of the cells within this envelope are analogous to that of the cell-first parallel projection.
The vertex-first parallel projection of the 16-cell into 3-space has an octahedral envelope. This octahedron can be divided into 8 tetrahedral volumes, by cutting along the coordinate planes. Each of these volumes is the image of a pair of cells in the 16-cell. The closest vertex of the 16-cell to the viewer projects onto the center of the octahedron.
Finally the edge-first parallel projection has a shortened octahedral envelope, and the face-first parallel projection has a hexagonal bipyramidal envelope.
Regular polytope
In mathematics, a regular polytope is the generalisation of the regular polygon. Like other polytopes it may have any natural number of dimensions. For example, a two-dimensional regular polytope is a regular polygon, and a three-dimensional regular polytope is a regular polyhedron. Like with the regular polygon, there are certain kinds of symmetries. Regular polytopes have regular facets (faces to speak from the 3D viewpoint), and their vertex figures are regular.
The simplest of the six convex regular 4-polytopes are the pentachoron and tesseract.
Moudud Ahmed
Moudud Ahmed (May 24, 1940 – March 16, 2021) was a Bangladeshi politician. He was a member of the Jatiya Sangsad between 1979 until 1982, 1986 until 1996 and 2001 until 2006.
Ahmed was the Prime Minister of Bangladesh from 1988 to 1989 as part of General Ershad's Jatiyo's party. He was also the Minister of Law, Justice and Parliamentary Affairs as part of the Bangladesh Nationalist Party (BNP) of Begum Khaleda Zia's term between 2001 and 2006. In 2010 he became one of the leaders of the BNP.
From 1989 until 1990, Ahmed was Vice President of Bangladesh during the final year of Hussain Muhammad Ershad presidency.
Ahmed was hospitalized for lung congestion and kidney problems in Singapore on February 1, 2021. He died a month later on March 16, at the age of 80.
Ziaur Rahman
Lieutenant-General Ziaur Rahman, Bir Uttam, Hilal-i-Jurat ( Ziaur Rôhman; January 19, 1936–May 30, 1981) was a Bangladeshi war hero, politician and statesman. He was the President of Bangladesh from 1976 until 1981 and founded the Bangladesh Nationalist Party (BNP), one of the two largest political parties in the country. His widow, Begum Khaleda Zia, has been Prime Minister of Bangladesh three times.
Vertex figure
In geometry, a vertex figure is the figure that results when a corner of a polyhedron or polytope is sliced off.
Khaleda Zia
Begum Khaleda Zia (; born September 5, 1945) is a former Prime Minister of Bangladesh. She was Prime Minister from 1991 to 1996, and also from 2001 to 2006. She was the first woman Prime Minister in Bangladesh. Zia is the widow of assassinated President of Bangladesh Ziaur Rehman. She leads his old political party, the Bangladesh Nationalist Party (BNP).
Bush Hill Park railway station
Bush Hill Park railway station is in the London Borough of Enfield in north London. It is in Travelcard Zone 5, on the Enfield Town branch of the Lea Valley Lines. The station, and all trains serving it, is operated by London Overground.
American lobster
The American lobster ("Homarus americanus") is a species of lobster are found in the Atlantic Ocean on the east coast of North America.
Canadian English
Canadian English is the type of English that is used by Canadians.
It is like American English in terms of vocabulary, but its grammar is like that of British English.
Canadian English is generally taught in schools using British ways of spelling, such as colour, flavour, and so on. However, the word themselves are usually American, in part because Canadians watch a lot of American TV shows and listen to a lot of American pop music. Rarely, the British form of words may be replaced with American forms, such as plow, program, and so on.
The main exception to this rule is terms related to cars and the auto industry. Because Canada's auto industry has always been dominated by American firms, Canadians use American words and spelling for such terms. Canadians and Americans spell the outer rubber portion of a wheel as "tire" instead of "tyre", put "gasoline" or "gas" in their vehicles instead of "petrol", store items in the "trunk" instead of the "boot", and may drive a "truck" instead of a "lorry".
Canadian English is different from other forms of English in its spoken form also. The dialects vary from sounding overtly English to an indistinguishable form very similar to those spoken in the northern states.
Asian arowana
The Asian arowana ("Scleropages formosus") is a species of fish that live in slow moving streams and creeks in Southeast Asia and Australia; Borneo, Malaysia, Sumatra and Thailand.
Javan hawk-eagle
The Javan hawk-eagle ("Nizaetus bartelsi") is a medium-sized dark brown raptor in the family Accipitridae. The Javan hawk-eagle is the national bird of Indonesia.
The Javan hawk-eagle is believed to be monogamous. The female usually lays one egg in a nest high on top of a forest tree. Their diet consists mainly of birds, lizards, fruit bats and mammals.
Uttarkashi district
Uttarkashi District (), also known as Uttar Kashi District, is a district of Garhwal division of the Uttarakhand state in northern India. Its headquarters are at Uttarkashi city.
Uttarkashi District town is high in the Himalaya range. The source of both the Ganges and Yamuna rivers are in the district. These attract thousands of Hindu pilgrims. The town is on the main route to Gangotri, has many Hindu temples, and is thought to be an important Hindu pilgrimage centre.
The 2011 census said that 329,686 people live in Uttarkashi district. This is around the same amount as the nation of Belize. Because of this, it is 567th in India by the amount of people who live there (out of a total of 640).
Simplex
In geometry, a simplex (plural: "simplices" or "simplexes"), sometimes called "n-simplex" is the "n"-dimensional analogue figure of the triangle. A triangle is a 2-simplex. The 0-simplex is the point, the 1-simplex is the line segment (line connecting two points). The 3-simplex is the tetrahedron, and the 4-simplex is the pentachoron.