The first two questions were successfully completed. Only the third question remains: it is required to draw a polygon with positive 17 only with a ruler.

The young man racked his brains, but made no progress.

Difficulties inspired fighting spirit. He finally solved the problem.

The tutor was shocked to see the students' homework. He said excitedly, "Do you know? You have solved the math problems left over from more than two thousand years! "

It turned out that the tutor handed the notes on this topic to the students because of mistakes.

Whenever I recall, the young man always said, "If someone told me that this is a math problem with a history of more than 2,000 years, I might never have the confidence to solve it."

This young man is Gauss, the prince of mathematics. One day, when the digital cards were having lunch together, the youngest one spoke.

Brother 0 said, "Let's take some photos together. What do you think? "

0' s brothers and sisters said in unison, "Good."

Brother 8 said, "Brother 0' s idea is really good. I will be a good person once. Shall I provide camera and film for Brother 8? "

Old 4 said, "Brother 8, it's good, but it's a little too much trouble. Better use my digital camera. That's settled. "

So, they got busy. Finally, they took pictures for them and immediately sent the digital camera to the print shop. The computer sister tried to ask them for money, but who paid for it? They stared at each other one after another. This is what the computer sister said, "A ***5 yuan, a * * * eleven brothers and sisters, how much does one person pay on average?"

Among the eleven of them, Lao Liu is the cleverest, and this time he is the first to work out the result. Do you know how it is worked out?