Tuesday, December 11, 2007
The Irish pound coin sketch
Sunday, November 25, 2007
Irish pound coin
The "Broighter Boat" issue for 2000.The Irish pound coin, which was introduced in 1990, residue the largest Irish coin introduced since decimalisation at 3.11 centimetres diameter and was 10 grams weight. The coin was nearly identical in dimensions to the old penny coin that circulated before 1971, and was quite similar in diameter to, but thinner, than the half-crown coin.
During the early movement of the coin, many payphone and vending machines which had been changed to accept the pound coin also accepted the old penny because of the similar size, the latter coin which was no longer legal gentle and had little value to collectors. As a result losses accrued to vending machine operators due to the substitution of the penny coin and further costs were associated with updating the machines so they would no longer accept the penny.
Sunday, November 18, 2007
British coinage
The earliest pound coin was introduced in 1983 to replace the Bank of England £1 banknote which was discontinued in 1984 (although the Scottish banks continued producing them for some time afterwards. The last of them, the Royal Bank of
Sunday, November 11, 2007
Axiomatic geometry
Sunday, November 4, 2007
What is geometry?
Sunday, October 28, 2007
Geometry
Sunday, October 21, 2007
Hyperrectangle
In geometry, an orthotope, (also called a hyperrectangle or a box) is the simplification of a rectangle for higher dimensions, formally defined as the Cartesian product of intervals.
A three-dimensional orthotope is also known as right rectangular prism, or cuboid.
An extraordinary case of an n-orthotope is the n-hypercube.
By analogy, the term "hyperrectangle" or "box" refers to Cartesian products of orthogonal intervals of extra kinds, such as ranges of keys in database theory or ranges of integers, rather than real numbers.