How do I depict centric extension?

Hello,

In math we are currently working on the topic of centric dilations/similar triangles/1st and 2nd ray theorem.

We have been given a task that is really beyond my capabilities.

The first picture is the task, the second picture is our teacher's notes, and the third picture is what I understood to some extent.

Our teacher literally said to us when we told him we didn't understand: "This will f*** your head."

So I'm hoping someone can help me here, because I think I'm missing some information to be able to process this.

Thank you.