If I stretch a circle into an oval, does the surface of the new shape increase or decrease?

If I stretch a circle into an oval, does the surface of the new shape increase or decrease? for example this one: example

1 Answer

A discrete example. Consider a square with the side $2$ units and the sides are foldable in units. If the square is stretched out to form a rectangle with sides $1$ and $3$ units. Obviuosly, the two figures will have the same perimeter, but the rectangle has smaller area.

Similarly, if a circle is stretched, the oval will have smaller area.