1. What is Circle Area?

The area of a circle is the amount of space enclosed within its circumference. It's measured in square units (square meters in this calculator).

2. How Does the Calculator Work?

The calculator uses the circle area formula:

Where:

• \( A \) — Area (m²)
• \( \pi \) — Mathematical constant (~3.14159)
• \( r \) — Radius of the circle (m)

Explanation: The area increases with the square of the radius, meaning doubling the radius quadruples the area.

3. Importance of Area Calculation

Details: Calculating circle area is fundamental in many fields including engineering, architecture, physics, and everyday applications like determining material requirements.

4. Using the Calculator

Tips: Enter the radius in meters. The value must be positive. The calculator will compute the area in square meters.

5. Frequently Asked Questions (FAQ)

Q1: What if I know the diameter instead of radius?
A: Divide the diameter by 2 to get the radius before using the calculator.

Q2: How precise is the calculation?
A: The calculator uses PHP's built-in π constant (about 15 decimal places) but displays results rounded to 2 decimal places.

Q3: Can I calculate partial circle areas?
A: This calculator gives full circle area. For sectors, you'd need additional information about the angle.

Q4: Why is area in square meters?
A: The calculator uses SI units. You can convert results to other units if needed.

Q5: What's the largest radius this can handle?
A: Theoretically very large, but practical limits depend on your computer's number handling capabilities.