longeur vs long

Question

BonjourIf voiture is feminine then isn't the use of longeur for wide correct. I was marked wrong.

Answer

Bonjour Norma,Could you add the link to the related lesson or exercise please? It would make it easier to see which question from the kwiz / exercise you are referring to.Bonne journée!

Answer

If you mean as an adjective, with voiture, it is < longue > not < longueur > (and not < long > either). Agreement needed.

With specific dimensions of the vehicle, the expressions:

As < être - dimension >, it is < (être) longue de (dimension)> Agreement needed

As < faire - dimension >, it is < (faire dimension) de long > or < de longueur > No agreement, just 2 different ways of expressing.

( There is a spelling error in your question, and that could also be marked incorrect if you were using < faire > )

Answer

Adding to Maarten's answer, notice that long/longue is an adjective whereas la longueur is a noun.