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Circle Area Formula:
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The area of a circle is calculated using the formula A = π × r², where A represents the area in square units, π (pi) is approximately 3.14159, and r is the radius of the circle. This formula allows you to determine the amount of space enclosed within a circle's circumference.
The calculator uses the circle area formula:
Where:
Explanation: The formula squares the radius (multiplies it by itself) and then multiplies that result by π to calculate the area.
Details: Calculating the area of a circle is essential in various fields including construction, landscaping, manufacturing, and interior design. It helps determine material requirements, space planning, and cost estimation for circular surfaces.
Tips: Enter the radius of the circle in feet. The radius must be a positive number. The calculator will automatically compute the area in square feet using the precise value of π.
Q1: What if I know the diameter instead of the radius?
A: The radius is half the diameter. If you know the diameter, divide it by 2 to get the radius before using the calculator.
Q2: How accurate is the π value used in the calculation?
A: The calculator uses PHP's built-in M_PI constant which provides π to about 14 decimal places, ensuring high precision in calculations.
Q3: Can I use this calculator for circles of any size?
A: Yes, as long as you provide a valid positive radius value, the calculator will work for circles of any size.
Q4: What are some practical applications of circle area calculations?
A: Calculating flooring for circular rooms, determining paint needed for circular surfaces, planning circular gardens or lawns, and designing circular structures.
Q5: How do I convert the result to other units?
A: To convert square feet to square meters, multiply by 0.092903. To convert to square inches, multiply by 144.