Answer:
What the boy measuring stick said when he saw the girl measuring stick was - Pleased to meter/metre you. It is a pun, or a play on words, because you'd normally say - Pleased to meet you, but given that these are not people, but rather measuring sticks, and what they do is measure stuff using meters as a unit of length, using the word meter instead of meet creates a funny effect because those words sound alike.
Explanation: