Hola Delia
The dictionary states that the noun "área" is feminine, and it is. The adjectives that accompany the noun are used in feminine, but with the definitive article you need "el" (when there is no other word in between the article and the noun, as explained in the lesson.) So, for example:
el área extensa
the wide area
but:
la extensa área
the wide area
I hope it clarifies it.
Saludos
Inma
