# Homework Help: Volume or area?

1. Jan 22, 2006

### Zenaide

Does pi/4(d^2) equal volume or area? OR neitheR?

2. Jan 22, 2006

### franznietzsche

Neither. I have no idea what that is supposed to represent. Of course, I'm assuming you're talking about a sphere(based on the presence of pi, and your reference to both volume and area), but you did not specify.

3. Jan 23, 2006

### Pengwuino

It represents an area but what area? I don't know, certainly no readily identifiable geometric shape.

4. Jan 23, 2006

### franznietzsche

Well, is it
$$\frac{\pi}{4 d^2}$$
or
$$\frac{\pi}{4} d^2$$

Assuming d is in meters, the first (how i read it) is not an area, the second(how i assume you read it, and i did not think of until you posted) is. The second is the area of a circle (where $$r= \frac{d}{2}$$), if d is a diameter.

@Zenaide: In the future you need to provide more information with a question. A single sentence will almost never be enough information for us to say anything definitive.

5. Jan 23, 2006

### Zenaide

$$\frac{\pi}{4} d^2$$
Okay That ^^^^^ is what I meant.... I had a sheet of equations but I don't have it and I can't find the equation for what that series of things equal... and I was using d as a diameter for a water tank.... SO I'm assuming the water tank is a cylnder. becuase it has a height and a diameter.

6. Jan 23, 2006

### franznietzsche

Then that would be the cross sectional area. The volume would be
$$V = \frac{\pi}{4} d^2 h$$

where h is the height in meters.