Which constant is used in the volume formula for a cylinder?

Which constant is used in the volume formula for a cylinder?

• A. Pi
• B. Euler's number e
• C. Golden ratio phi
• D. Zero

Answer: (A)

The main idea is that a cylinder’s volume comes from its base area times its height. The base is a circle, and the area of a circle is π times the radius squared (πr^2). Multiply that by the height to get V = πr^2h. The constant π is tied to circle geometry—it’s the ratio of a circle’s circumference to its diameter and is the universal factor in any circular area calculation. The other constants don’t apply here: e relates to exponential growth, φ is the golden ratio, and zero would imply no volume.

The main idea is that a cylinder’s volume comes from its base area times its height. The base is a circle, and the area of a circle is π times the radius squared (πr^2). Multiply that by the height to get V = πr^2h. The constant π is tied to circle geometry—it’s the ratio of a circle’s circumference to its diameter and is the universal factor in any circular area calculation. The other constants don’t apply here: e relates to exponential growth, φ is the golden ratio, and zero would imply no volume.