Breakdown of Ich weiß nicht, wovon der Text handelt.
ich
I
nicht
not
wissen
to know (a fact)
der Text
the lines / the text
Questions & Answers about Ich weiß nicht, wovon der Text handelt.
Why do we use wovon here instead of just translating "what" as was?
The verb handeln (when meaning "to be about") requires the preposition von. In German, you cannot end a sentence with a preposition like you do in English ("what the text is about"). Instead, when asking "about what" for an inanimate object or concept, you combine wo + von into the interrogative pronominal adverb wovon.
How does wovon relate to the hier- words we are learning in this lesson?
They belong to the same family of compound words! wovon is the question word ("about what?"). If you wanted to answer the question by pointing to a specific topic right in front of you, you would use the proximate adverb hiervon ("about this"). If you were referring to a topic mentioned earlier, you'd use davon ("about that").
Could I use the phrase es geht um instead of handeln von for this sentence?
Yes, you absolutely can, and it's very common! However, because the preposition changes to um, your compound word must also change. The sentence would become: Ich weiß nicht, worum es in dem Text geht. (Notice we add an r to make worum so the vowels don't crash together).
Why is the verb handelt at the very end of the sentence?