Final answer:
The area of a circle is calculated using the formula A=πr², which means the area is equal to pi multiplied by the radius squared. You should know the circle's radius to apply this formula, or you can find it by dividing the diameter by 2. Then, you square the radius and multiply by pi to calculate the area.
Step-by-step explanation:
The formula to calculate the area of a circle is A=πr².
This formula states that the area (A) is equal to the mathematical constant pi (π), approximately 3.14159, multiplied by the square of the circle's radius (r).
To use this formula, you need to know the radius of the circle. If you only know the circle's diameter (d), remember that the radius is half the diameter. Therefore, you can find the radius by dividing the diameter by 2. For instance, if the diameter is 10, the radius would be 5.
Finally, you square the radius and multiply by pi to get the area. In our example, the area would be 25π, or approximately 78.54 (using 3.14159 for pi).
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