geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

, a balbis is a geometric shape that can be colloquially defined as a single (primary) line that is terminated by a (secondary) line at one endpoint and by a (secondary) line at the other endpoint. The terminating secondary lines are at right angles to the primary line. Its parallel sides are of indefinite lengths and can be infinitely long. The word "balbis" comes from the ancient Greek word βαλβίς, meaning a rope between two posts used to indicate the start and finish of a race. The most common example of a balbis is the capital letter ' H', the eighth letter in the

ISO basic Latin alphabet The ISO basic Latin alphabet is an international standard (beginning with ISO/IEC 646) for a Latin-script alphabet that consists of two sets (uppercase and lowercase) of 26 letters, codified in various national and international standards and u ...

. It can also be seen in, for example, rugby posts and old-fashioned television antenna. Another type of balbis is the rectangular balbis, that may be loosely described as a

rectangle In Euclidean plane geometry, a rectangle is a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°); or a parallelogram containi ...

with one side missing. A rectangular balbis was used in the Olympic Games, as a throwing area and is described by

Philostratus II Philostratus or Lucius Flavius Philostratus (; grc-gre, Φιλόστρατος ; c. 170 – 247/250 AD), called "the Athenian", was a Greek sophist of the Roman imperial period. His father was a minor sophist of the same name. He was born probab ...

. In his book about the balbis (see References below), the Rev. P. H. Francis describes the balbis as "the commonest geometrical figure, more in evidence than the triangle, circle, ellipse, or other geometrical figure that has been studied from ancient times" and goes on to state that it "was known to but not studied by the ancient Greeks; and this geometrical figure has been neglected." His memorial illustrates a balbis and can be seen in St. Mary's Church,

Stoughton, West Sussex Stoughton is a village and civil parish in the District of Chichester in West Sussex, England located north west of Chichester east of the B2146 road, on a lane leading to East Marden. The parish has a land area of . In the 2001 census 631 peo ...

References

*{{Citation , last1=Francis , first1=Philip Harwood , title=The balbis: a neglected geometrical figure , url=https://books.google.com/books?id=4AioAAAAIAAJ , publisher=Mitre Press , isbn=978-0-7051-0117-2 , year=1971 The Rev. Francis was sometime vicar of

. Geometric shapes