1. What is Cylinder Surface Area?

The surface area of a cylinder is the total area of all its surfaces, including the two circular bases and the curved side. It's important in many practical applications like material estimation and heat transfer calculations.

2. How Does the Calculator Work?

The calculator uses the cylinder surface area formula:

Where:

• \( r \) — Radius of the cylinder's base
• \( h \) — Height of the cylinder
• \( \pi \) — Approximately 3.14159

Explanation: The formula combines the lateral surface area (2πrh) with the area of the two circular bases (2πr²) to get the total surface area.

3. Importance of Surface Area Calculation

Details: Calculating surface area is essential for determining material requirements (like paint or wrapping paper), heat transfer calculations, and in various engineering applications.

4. Using the Calculator

Tips: Enter the radius and height in the same units. The result will be in square units of whatever unit you used for input. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between lateral and total surface area?
A: Lateral surface area only includes the curved side (2πrh), while total surface area includes the bases as well (2πrh + 2πr²).

Q2: Does this work for hollow cylinders?
A: For hollow cylinders (tubes), you'd need to calculate both inner and outer surface areas separately.

Q3: What if my cylinder is lying on its side?
A: The formula remains the same as orientation doesn't affect the total surface area.

Q4: How precise is the π value used?
A: We use PHP's built-in pi() function which is precise to about 14 decimal places.

Q5: Can I use different units for radius and height?
A: No, both should be in the same units to get a meaningful result in square units.