If
a square and a rectangle are
of the same Perimeter… Then,
which one of the polygons is larger in Area?
Explain!
Square perimeter = 4s,
rectangle perimeter = 2((s-n)+(s+n))
= 4s.
As shown below, C+n2 = A,
then C < A,
and B+C (=rectangle) < B+A (=square).
Thus, the rectangle is less than the Area of
the square by the square of the difference
of their sides (n2).
The
first electronic mail, or "e-mail",
was sent in 1972 by Ray Tomlinson.
It was also his idea to use the @ sign
to separate the name of the user from the
name of the computer. Much earlier still,
the @ sign
was (supposedly) a monastic ligature or
abbreviation in Latin handwritings of the
Middle Ages. Writers and amanuenses had
used it to abbreviate the Latin "ad" (at,
to), a common word at that time, due to
a lack of space or for convenience sake.
Then, the @ sign
appeared on the Iberian Peninsula in the
XVth century. Spanish and Portuguese merchants
dealt in cattle and wine, thereby using
a measure for weighing solids and liquids
called "arroba". The word is
of Arabic origin (ar-roub) and
means "a quarter". Later, the @ sign
was used by grocers and accountants throughout
the English-speaking world to indicate
a rate, or cost per unit, as in "10
gal. @ $3.45/gal." (ten
gallons at three dollars and forty-five
cents per gallon). Here are some sampling of the many names
of @,
world-wide:
In French, @ sign
is called "arobase". Probably derived
from Spanish "arroba".
In Danish it's either called "alfa-tegn" (alpha-sign)
or "snabel" (elephant's trunk).
In German, @ is
most often called either "Affenschwanz" (monkey's
tail) or "Klammeraffe" (hanging
monkey).
In Hebrew, it's most often
either a "shablul" or "shablool" (snail)
or a "shtrudl" (strudel, that is,
the pastry). In both cases, it's something
that is rolled up. Italians call @ "chiocciola" pronounced "kee-AH-cho-la" (snail),
and sometimes, "a commerciale" (business
a). Japanese borrows words freely
from foreign languages, though usually with
a distinctly Japanese pronunciation. Japanese
accounting and computer people normally call @ "atto
maaku" (at mark).
In Russian, the official term
for @ is "a
kommercheskoe" (commercial a), but it
is usually called "sobachka" (little
dog or "doggie").
MATEMAGICA blackline
masters for making over 25 funny math puzzles! A collection
of incredible puzzles and optical illusions with easy-to-follow
instructions (in Italian). Ideal for math
workshops.