Chapter 40 Section 40

On the table, there are three pieces of paper cut into triangles with scissors.Because they are stacked and cut, the shapes of the three sheets are exactly the same.Yu Chuan first used two of them to make a parallelogram, and then put the last one together to form a rectangle. "Now you understand? When you put the three interior angles of a triangle together, you get a straight line. That's one hundred and eighty degrees. That's the basis of everything. And a quadrilateral can be divided into two triangles, so its interior angles That's twice 180 degrees, or three hundred and sixty degrees. Likewise, for a pentagon—"

Yukawa explained in detail, but another scene appeared in Kyohei's mind. Last night, before going back to bed, Gongping ran to his uncle's room to have a look.At that time, my uncle's family seemed to be discussing something.Although he couldn't quite understand the content of the conversation, Kyohei still heard a sentence in it. The teacher has noticed it.The person who said this was Uncle Shigeharu. The moment Kyohei heard those words, his legs felt weak.Kyohei managed to stand still with his knees trembling.He turned away and walked softly back down the corridor. Back in the house, Gongping immediately got into bed.He tried his best to suppress the uneasiness in his heart, and his heart was pounding.Adults never tell the truth to children.However, Gong Ping knew very well what would happen next.This is by no means a good thing.Otherwise, my uncle's tone of voice would not have sounded so ominous.

When he came back to his senses, Tang Chuan had stopped talking.Kyohei raised his head and found that the physicist was staring at his own face with his hands on his chin.His eyes seemed to be observing something. Gongping scratched his head and glanced at the table.On the open notebook, some graphics are drawn.The last picture is a nonagon. "I'm asking you, how many triangles can a nonagon be divided into. But looking at you now, I guess you can't answer it?" "Ah, uh..." Gongping quickly picked up the mechanical pencil, but didn't know how to do it. "Draw a line from the vertex of one angle to all the other angles. Adjacent angles are excluded. Since only six lines can be drawn, seven triangles can be drawn in total. The sum of the interior angles is equal to one hundred and eighty degrees times Seven, one thousand two hundred and sixty degrees." Sitting across from him, Tang Chuan didn't even turn his notebook back, and wrote down the formula in the notebook backwards. "What happened to you today? Why have you been absent-minded? If this continues, your homework will never be finished. Do you have something on your mind?"

"It's nothing on my mind..." Gongping didn't know how to prevaricate.At this moment, the child's mobile phone next to the notebook rang.Gongping couldn't help but breathe a sigh of relief.Looking at the caller ID, Gong Ping found that it was a completely unfamiliar number. "Why not answer?" Tang Chuan asked. "My family told me that if you see an unfamiliar number, don't answer it." "Huh? The calling number is not 090xxxxxxx, is it?" Tang Chuan said a series of numbers in one breath. Gongping was taken aback.He looked at the caller ID and said, "Exactly."

"Since it's this number, there's no problem. This call is for me." Tang Chuan snatched the phone from Gongping, and answered it calmly, "Hi, I'm Yu Chuan... well, I'm It's all right. Did you find out anything after that?" While talking on the phone, Yu Chuan got up and walked out of the room. What are you doing, using other people's mobile phones without authorization——Kyohei pouted, got up and walked to the door, and opened the door slightly. With his back to the door, Yu Chuan was talking on the phone. "...Is that the case? Hagiki, isn't it... well, I'm afraid it is. It's as I guessed. There must be something wrong with the family... Well, then I will trouble you."

Gong Ping closed the door and tiptoed back to his previous position.Like last night, his body trembled again. The teacher had already noticed it——in Kyohei's mind, Shigeji's voice echoed again.