Answer:
I have never actually seen a zigzag ruler, but I would assume to make zigzag lines.
Explanation:
You would call a bus a guagua in C. Cuba.
In Spanish, the word guagua means a bucket, however, in colloquial everyday speech, the Cubans also refer a bus as a guagua. The word is not that new, actually, as it has been used with this meaning since the 19th century in Cuba
