1. What is a Semicircle Area?

A semicircle is half of a circle formed by cutting a whole circle along its diameter. The area of a semicircle is exactly half the area of a full circle with the same radius.

2. How Does the Calculator Work?

The calculator uses the semicircle area formula:

Where:

• \( \pi \) — Mathematical constant (approximately 3.14159)
• \( r \) — Radius of the semicircle

Explanation: The formula calculates the area of a full circle (πr²) and then divides by 2 to get the area of the semicircle.

3. Practical Applications

Details: Semicircle area calculations are used in architecture (designing arches, windows), landscaping (designing garden beds), and construction (calculating materials needed for semicircular structures).

4. Using the Calculator

Tips: Measure the radius from the center of the straight edge (diameter) to any point on the curved edge. Enter the radius in feet for square footage calculation.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between radius and diameter?
A: The radius is half the diameter. The diameter is the full length across the circle through the center.

Q2: Can I use this for metric measurements?
A: Yes, but the result will be in square meters if you enter radius in meters instead of feet.

Q3: How accurate is this calculation?
A: The calculation is mathematically precise. Any inaccuracy comes from how precisely you measure the radius.

Q4: What if I only know the diameter?
A: Divide the diameter by 2 to get the radius before using the calculator.

Q5: Does this work for partial semicircles (less than half)?
A: No, this calculator is specifically for perfect semicircles (180° arcs).