1. What is the Area of Annulus?

An annulus is the region between two concentric circles. The area of an annulus is the difference between the areas of the larger circle and the smaller circle. This calculator computes the area using the perimeter of the annulus and the inner circle radius.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Area of Annulus (m²)
• \( P \) — Perimeter of Annulus (m)
• \( r_{Inner} \) — Inner Circle Radius of Annulus (m)
• \( \pi \) — Archimedes' constant (approximately 3.14159)

Explanation: The formula calculates the area by first determining the outer radius from the perimeter, then subtracting the area of the inner circle from the area of the outer circle.

3. Importance of Annulus Area Calculation

Details: Calculating the area of an annulus is important in various engineering and architectural applications, such as designing pipes, washers, and ring-shaped structures. It helps in material estimation and structural analysis.

4. Using the Calculator

Tips: Enter the perimeter of the annulus and the inner circle radius in meters. Both values must be positive numbers. The inner radius can be zero, which would represent a solid disk.

5. Frequently Asked Questions (FAQ)

Q1: What is an annulus?
A: An annulus is a ring-shaped object, the region bounded by two concentric circles.

Q2: Can the inner radius be larger than the outer radius?
A: No, by definition, the inner circle must be smaller than the outer circle in an annulus.

Q3: What units should I use?
A: The calculator uses meters for both input values, but the formula works with any consistent unit system.

Q4: What if I have the outer radius instead of the perimeter?
A: You would need to use a different formula: A = π(R² - r²), where R is the outer radius and r is the inner radius.

Q5: Can this calculator handle decimal inputs?
A: Yes, the calculator accepts decimal values for more precise calculations.