How will the length of the circle change if: 1) its radius is doubled. 2) reduce its diameter by 4 times.

1) Knowing that the circumference is 2 * π * R, where R is the radius of the circle, we can say. that if the radius is doubled, then the circumference will also double.
2) Knowing. that the circumference is equal to π * D, where D is the diameter of the circle, we can say that if the diameter of the circle is reduced by four times, then the circumference will also decrease by four times.

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