If the circumference of a circle is known to be 4 π, find its area

Let R be X
2πr=4π
r=2
S circle = π R ^ 2
=4π
=12.56

Given that the circumference of a circle is 60 meters, find its area

According to the formula: the circumference of the circle = 2 Π R. substituting the circumference 60 into the formula, we can get: 60 = 2 Π R, so r = 60 Π 2
two
According to the area of the circle = Πr, the area of the circle can be calculated
two
Formula: (60 ／ 2 ／Π) * Π
two
If you make π about 3.14, the formula is: (60 ／ 2 ／ 3.14) * 3.14

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