What is the area enclosed by the ellipse $4x^{2} + 9y^{2} = 36$?

Explanation

1. 01

   Divide by 36: $\frac{x^{2}}{9} + \frac{y^{2}}{4} = 1$, so $a = 3$ and $b = 2$.

2. 02

   Area $= \pi ab = 6\pi$ square units.