# EMERGENCY-formulas for perimeters of ovals

1. Apr 6, 2006

### antipreplaydee

Can some one help me.

2. Apr 6, 2006

### antipreplaydee

i need a formula to find the perimeter of an oval

3. Apr 6, 2006

### antipreplaydee

cmon. i seriously need help.

4. Apr 6, 2006

### Integral

Staff Emeritus
Approximately

$$p =2 \pi \sqrt { \frac {a^2 + b^2} 2}}$$

Where a and b are the "radius" .

If you want exact you will need to be able to evaluate an elliptic integral... You up for that?

5. Apr 6, 2006

### HallsofIvy

Staff Emeritus
What, exactly, do Y0U mean by "oval". I might be inclined to assume a quadratic formula, but it seems clear that you do do not p[/b}] \pmean tnat

6. Apr 6, 2006

### Kb1jij

Do you mean an ellipse? This is a specific type of an "oval" and is like a streched out circle. It follows the formula:
$$\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1$$
Unfortunately, there is not a simple exact formula for the perimeter of an ellipse. You might want to check out this website for more information: http://home.att.net/~numericana/answer/ellipse.htm#elliptic

7. Apr 6, 2006

### HallsofIvy

Staff Emeritus
Until you can say what you mean by "oval" I'm afraid this makes no sense at all.

8. Apr 6, 2006

9. Apr 6, 2006

### Integral

Staff Emeritus
I have made a call on this thread. I will assume that by "oval" means ellipse. Further, this is not a homework question. Until the OP checks back in there is not really much more to be said.

The formula I provided is for the perimeter of an ellipse. The precise method, which may well be in fact the basis for the name Elliptic Intergral, is beyond fundamental math and may be best done numerially. Thus it may provide the basis for a broader dissussion of an interesting topic.