Rumanujan's Circumference of an Ellipse calculator approximates the circumference of an ellipse based on one of Rumanujan's approximations.
INSTRUCTIONS: Choose units and enter the following parameters;
Circumference of an Ellipse (C): The calculator returns the circumference or perimeter of the ellipse in meters. However, this can be automatically converted to compatible length units via the pull-down menu.
In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve. As such, it is a generalization of a circle, which is a special type of an ellipse having both focal points at the same location. The shape of an ellipse (how "elongated" it is) is represented by its, which for an ellipse can be any number from 0 (the limiting case of a circle to arbitrarily close to but less than 1.
The circumference of an ellipse has been approximated in several simple formulae including this one by the famous mathematician Rumanujan. The the formula for the circumference of an ellipse used in this calculator is:
`C = pi * [3* (a+b) - sqrt((3*a+b) (a+3*b))]`
Description of an ellipse is from Wikipedia (en.wikipedia.org/wiki/Ellipse)