1 ) Print out the three ellipses . 2 ) Calculate Eccentricity " out- of - roundness" ) E = 2 0 ECCENTRICITY is the amount of flattening of an Ellipse , or how much the shape of the ellipse deviates from a perfect circle . A circle , which has only one central focus ) has an eccentricity* of O . The greater the eccentricity , the less circular the Ellipse . a ) Measure the distance between the faci for each Ellipse . Put the data in the chart below . b ) Draw a line across the faci to the edges of the Ellipse . This is the major axis . Measure the major axis and divide by two , this is the semi - major axis ( a) . [ ] Calculate the eccentricity . It should be between O and 1. SHOW WORK IN THE DATA TABLE! Ellipse Distance Length of semi - ECcentricity ( distance between Which is roundest ? between facil major axis ( CITY ) foci /'length of major axis" Least round ? SHOW YOUR WORK