Template:POTD/2007-01-20
Picture of the day archives
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2007 January
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Picture of the day
An
animated image
showing the definition of
pi
. A
number line
is
marked off
by a
circle
of unit
diameter
. Starting from
zero
, the circle "unrolls" its
circumference
. At one full
turn
, the unrolled
circumference
has extended to the point we call π. This number is
real
but
irrational
,
transcendental
, and cannot be
constructed
with
compass and straightedge
.
Animation credit:
John Reid
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