You can draw this yourself. From the area formula of an ellipse, we can know that "an ellipse has a long axis and a short axis A and B, and the formula for calculating their area is s=πab". The change rates of the long axis and the short axis interact inversely, and become larger and larger (this is similar to a square, so you can treat it as a square, which can be barely explained by the area of the square), so you can use its formula to calculate it. (Because an ellipse has two axes, the maximum solid area has two axes).