1. What is the Perimeter of a Semicircle?

The perimeter of a semicircle is the total length around the shape, which includes both the curved part (half the circumference of a full circle) and the straight diameter.

2. How Does the Calculator Work?

The calculator uses the semicircle perimeter formula:

Where:

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

Explanation: The formula combines half the circumference of a full circle (πr) with the diameter (2r) to get the total perimeter.

3. Importance of Perimeter Calculation

Details: Calculating the perimeter of a semicircle is important in various fields including architecture, engineering, and design where curved structures are involved.

4. Using the Calculator

Tips: Enter the radius of the semicircle. The value must be positive and greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why do we add both πr and 2r in the formula?
A: The πr represents the curved part (half the circumference), while 2r represents the straight diameter part of the semicircle.

Q2: What units should I use for the radius?
A: You can use any unit of length (cm, m, inches, etc.), and the perimeter will be in the same units.

Q3: Can I use diameter instead of radius in the calculation?
A: Yes, but you would need to convert diameter to radius first (radius = diameter/2) before using the formula.

Q4: How accurate is the calculation?
A: The calculation uses the precise value of π available in PHP, making it highly accurate for practical purposes.

Q5: What if my semicircle is not a perfect half circle?
A: This formula only applies to perfect semicircles. For irregular shapes, more complex calculations are needed.