Hi John, When you write area, you mean circumference, I suppose.
Your fomula is not so accurate as the formula of Ramanujan: ( 3(a + b) - sqrt[ (a + 3b)(3a + b) ] ) pi De greatest deviation according to this formula is 0.4 % (when the minor axe is zero). According to your formula the deviation varies from 21,5 % (when the minor axe is zero) to 0 % (when the minor axe = the major axe). Only for values of minor axe and major axe with a ratio < 53/47 (an analemmatic sundial near the pole) your formula is more accurate then the formula of Ramanujan. Regards. ============================= Willy Leenders Kloosterlaan 60 B 3500 Hasselt Belgium 50.893722 N 5.34986 E Tel. (00)(#)(0)11 72 04 47 [EMAIL PROTECTED] ============================= John Carmichael wrote: > Hi All > > At risk again of exposing my limited math skills, I was wondering if it would > be possible to get an approximation of the area of an elipse by the following > method: > > Average the length of the major an minor axises and then apply the formula > for the area of a circle to this value, treating it as the diameter of a > circle. > > example: If the major axis equals 4 cm. and the minor axis equals 2 cm. then > their average length is 3 cm. The area of a circle is pi times the diameter. > So , 3 times pi = 9.42 square cms. > > Would somebody check to see how close this is to the actual value? > > (p.s. I'm thinking that you could use the formula for the circumference of a > circle in the same way to get the circumference of an elipse. ) > > Thanks > > John L. Carmichael > 925 E. Foothills Dr. > Tucson Arizona 85718 > USA > > e-mail: [EMAIL PROTECTED] > Tel: 520-696-1709 >
