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Area and circumference of a circle

circle

circle d r O C (O, r)
rradius
ddiameter
Ocenter

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radius

r =

diameter

d =

area

A =

circumference

C =

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Calculation procedure

Formulas

circle

area
$$ A = \pi r^2 = \frac{\pi d^2}{4} $$
circumference
$$ C = 2 \cdot \pi r = \pi d $$
diameter
$$ d = 2 \cdot r $$
$$ \pi \doteq 3.14 $$

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