Pi is also an angle of 180 degrees.
That's when the angle is in radians. e.g. 180 degrees = pi radians
You can approximate pi like so:
Get a matchstick and measure it. Then get a piece of paper and draw parallel lines on it, so that they are the same distance apart as the length of the match. Then flip the match onto the piece of paper and note whether it crosses a line. Keep doing this until you get bored, but the more times you do it, the better your estimation will be.
You can use your results to approximate pi by knowing that the probability of it landing on a line is 2/pi. There's something for you to do when you're bored!
]]>e^(i*pi)=1
Of the five numbers considered important in mathematics, this number relates four.
I think this equation was given by Loenard Euler.
This, I think, is a result of
e^(i*theta) = cos (theta) + i sin(theta)
and
Abraham de Moivre's theorem, according to which
(Cos(theta)+i*sin(theta))^n = cos n(theta) + i*sin n(theta)
which can be written as
e^(n*i*theta) = Cos n(theta) + i*sin n(theta)
Also, if you're interested, √i=(1+i)/√2.
]]>0²=0, so √0=0.
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