The area of a circle is calculated using the following formula: $$ Area = \pi r^2 $$ Where \(r\) is the radius of the circle and \(\pi\) is the mathematical constant pi. The radius of a circle is the distance from the center of the circle to any point on the perimiter.

The formula explained: take the square of the radius and multiply it by \(\pi\). If you are not familiar with the \(\pi\) (pi) symbol, please visit this page: What is Pi?

Enter the radius of a circle below to see its area.

The area of the triangle with these measurements is

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