Which construction could this be?

You are correct it is Inscribed Hexagon

9514 1404 393

  45, 56, 67

Step-by-step explanation:

Terms of an arithmetic sequence have a common difference. That is, the next term is found by adding that difference to the previous term.

Here, the difference is 12 -1 = 11, so each term is 11 more that the previous one. The next terms are found by repeatedly adding 11.

  34 + 11 = 45

  45 + 11 = 56

  56 + 11 = 67

The next three terms are 45, 56, 67.