Learn Finnish: Tämä helma on viisi senttiä leveä. - This hem is five centimeters wide.

When using an adjective of dimension like leveä (wide), pitkä (long), or korkea (high), Finnish conveniently uses the exact same structure as English: Number + Unit + Adjective. Therefore, viisi senttiä leveä mirrors the English phrasing perfectly.

Why is leveä in the basic nominative case when the word right before it (senttiä) is partitive?

The adjective leveä describes the subject of the sentence, helma (hem), which is in the nominative case. It does not agree with the measurement unit (senttiä). The phrase viisi senttiä simply acts as an extra piece of information telling us how wide the hem is.

As a quick refresher, why is the unit senttiä in the partitive case?

In Finnish, any number greater than one requires the noun directly following it to be in the partitive singular. Because the number is viisi (five), the base word sentti takes the partitive ending to become senttiä.

Does senttiä mean centimeters or cents (as in money)?

It means both! The word sentti is used for both the unit of length (centimeter) and currency (cent). You just have to rely on context—since we are measuring how wide a hem is here, it clearly means centimeters.