Which adjective correctly describes the feminine noun in the nominative case?

For example, the sentence "Er fand eine alte, verfallene Hütte"

The adjective 'alte' is the correct word to use here because it is in the nominative case, feminine form. This adjective describes the noun 'Hütte', which is a feminine noun. 'Alt', the base form of the adjective, 'alten', the masculine or dative plural form, and 'altes', the neutral form, would all be incorrect in this context because they do not match the gender of the noun being described.