Area of an Ellipse

You know the formula for the area of a circle of radius R.   It is Pi*R².

But what about the formula for the area of an ellipse of semi-major axis of length A and semi-minor axis of length B?   For example:

(x²/A²) + (y²/B²) = 1.

The area of such an ellipse is
Area = Pi * A * B ,
a very natural generalization of the formula for a circle!

Send any comments or questions to: David Pleacher