Do you know about case system in Russian? Each noun in Russian should take one of six cases (for both single and plural) according to its role in a sentence. Each case has specificity in spelling. It is like in English "I" and "me", "We" and "us".

Here are all forms of the word "расстояние".

Basically it means that you can not correctly translate one word from a sentence. You need to translate the whole sentence.

The "default" case (which is used in vocabularies) is nominative. Nominative plural of this word is "расстояния".