Ellipse and Eccentricity

① This GeoGebra example dynamically illustrates the ellipse and its eccentricity, showing how the shape changes with the eccentricity value. ② Core mathematical concepts include the definition of an ellipse (sum of distances to two foci is constant), semi-major axis a, semi-focal distance c, and eccentricity e = c/a. ③ Construction: Based on the summary, the example uses an ellipse object e and variables a and c (likely controlled by sliders), allowing users to adjust these parameters and observe the resulting ellipse shape, thereby visualizing the transition from a circle (e=0) to a highly elongated ellipse (e approaching 1). ④ Suitable for high school analytic geometry or introductory college geometry, useful for classroom demonstrations or self-study to build intuitive understanding of ellipse properties.