Ellipse Diagram with Foci and Axes

A clear diagram illustrating the key features of an ellipse. It highlights the two focal points, F1 and F2, and the center, C. A line segment, labeled 'r', extends from one focus (F1) to a point on the ellipse, with an angle 'theta' indicated at F1. The major axis is shown with segments d1 and d2, representing the distances from the ellipse's vertices to the foci along this axis. The diagram effectively visualizes fundamental geometric properties of an ellipse.

ellipse - foci - center - major axis - geometry - mathematics - diagram - conic section - polar coordinates