Xueba, I beg you to go and escort him quickly!

Yue Pingting was at a loss for words, "I, I...I..."

Xu Heng scratched her nose, "Show me the title."

The topic catches the eye.

Hey!

A lot of words.

my country has a long history of Jinshi culture, and Yinxin is one of the representatives of Jinshi culture. The shape of Yinxin is mostly cuboid, cube or cylinder. However, the shape of Guanyun Dugu Xin in the long period from north to south is "semi-regular polyhedron" (Figure 1). .

A semi-regular polyhedron is a polyhedron enclosed by two or more regular polygons.

The semi-regular polyhedron embodies the symmetry beauty of mathematics.

Figure 2 is a semi-regular polyhedron with 48 edges, all its vertices are on the surface of the same cube, and the edge length of this cube is 1.

Then how many faces does this semi-regular polyhedron have, and what is the length of its edges?

Xu Heng looked at the picture.

Yue Pingting was on the side, watching with big eyes blinking.

"So many words! There are such graphs, and what about Dugu Xin? In order to test us in mathematics for the college entrance examination, even the history is taken out."

"Look at this picture, it should be a cultural relic, right?"

Xu Heng gave Yue Pingting a white look, "Does Dugu Xin know?"

Yue Pingting shook her head.

Xu Heng, "This is a great figure in history, and he is also the best old man in history!"

Yue Pingting, "How awesome can it be?"

Xu Heng, "The four daughters of his family are all queens. He was an important general in the Northern Zhou Dynasty. It is said that some students found this seal on their way home from school. At first they thought it was a strange stone. Thoughts are priceless."

"It's still on display in the museum."

Yue Pingting's eyes lit up, and she became interested.

"Knowledge points have increased again!"

"By the way, Xu Heng, are you always thinking like this when you are doing the questions?"

Xu Heng rolled his eyes, "I'm just thinking wildly? I'm doing this for you! To popularize knowledge for you."

Yue Pingting, "..."

Xu Heng, "Okay, let's not talk too much, let's look at the questions. The previous ones are all nonsense, and the latter ones are the real ones, which are related to mathematics. They examine the understanding of a polyhedron from three dimensions."

"If you know Euler's formula, this question is very simple!"

Yue Pingting lay beside Xu Heng, listening carefully.

Xu Heng was lying down, "According to Euler's formula v+fe=2!"

Yue Pingting, "Wait, what what?"

Xu Heng, "v represents the vertex, f represents its face, and e represents the number of edges."

"Let me ask you, the number of edges is 48, so how many vertices are there?"

Yue Pingting, "Huh? How much? Let me see... Let me see... 1,2,3,4, [-], [-], [-]..."

Xu Heng, "What are you doing?"

Yue Pingting curled her lips, "I'll count them!"

Xu Heng, "Don't count, it's 24. If you know the number of fixed-point edges, then this face will come out, right? The numbers go one step further, and there are 26 faces in total."

"do you understand?"

Yue Pingting said stupidly, "Tell me your story first, and I'll digest it by myself. What's next!"

Xu Heng, "This question is about the length of the ridge. It depends on Figure 2. Let's make a front view of it."

Xu Heng began to draw pictures.

Yue Pingting could barely keep up with her thoughts.

"Yeah! You continue."

Xu Heng, "It's just a simple calculation, so the final answer is the root number 2-1! You digest it first, ha... I'll go back to sleep again."

Yue Pingting looked at the question and blinked her eyes wide.

She looked at the title, then at Xu Heng.

"Boom~~~!"

Couldn't help but gave him a sip.

"you are awesome!"

Xu Heng smiled without opening his eyes.

Yue Pingting continued to read the questions, and she slumped beside Xu Heng.

Much like a cat.

When Xu Heng opened his eyes again, Yue Pingting looked at him bewilderedly.

"Don't say it, take a closer look, you're pretty handsome!"

Isn't this nonsense!

"But I've never seen it so close! The more you look at it, the more handsome it is."

Ok!

Xu Heng smiled, please continue with your rainbow fart.

By the time they got up, it was almost four o'clock in the afternoon.

He Junfei came looking for him.

"Xu Heng..."

He holds a test paper in his hand.

A high exam paper.

Ever since he knew about Xu Heng's results, He Junfei became anxious.

He desperately wants to improve himself.

At the same time, he also wanted to prove Xu Heng's true strength.

All this time, he didn't test Xu Heng much.

He knew that Xu Heng must be stronger than himself!

But to what extent it is so powerful is unknown.

"." Xu Heng!are you free?I want to ask you a few questions. "

"College entrance exam questions, can you?"

Yue Pingting was surprised, "Are you also doing college entrance examination questions recently?"

Are you doing it recently?

and also?

He Junfei, "Er...you mean, Xu Heng too?"

Yue Pingting smiled, and hurriedly waved her hands, "No, no, Xu Heng can't do it. It's me. I'll just look at the college entrance examination questions I've learned so far, find some, I can't, let Xu Heng tell me."

He Junfei's heart skipped a beat.

What happened to the students at Spruce High School?

Yue Pingting, you are only a sophomore in high school, you only read the math questions in the college entrance examination? !

I'm behind again?

???

"Even ordinary students in the second year of high school in your school have started to work on the college entrance examination questions?"

He Junfei was dumbfounded.

He also thinks he is very good!

But I never expected that ordinary classmates would start.

He felt that he had been greatly insulted.

For a while, He Junfei stared at Xu Heng, feeling that the gap between them was getting bigger!

It is no longer something that can be measured by a college entrance examination paper!

Xu Heng, "Do you have a question to ask me? Come on, hurry up and ask, hurry up and leave, we are still waiting for dinner."

One of the purposes of He Junfei's questioning was disintegrated.

But his other purpose is to know the answer!

Pass the test paper in front of Xu Heng, "This question."

Xu Heng glanced around.

topic:

The ancient Chinese "Book of Changes" used "gua" to describe the changes of all things.

Each "heavy hexagram" is composed of 6 lines arranged from bottom to top. The lines are divided into yang line "—" and yin line "one by one". , then what is the probability that the heavy hexagram has exactly 3 yang lines?

(Qian Dede) He Junfei, "I don't know much about "Book of Changes"..."

Yue Pingting covered her mouth and smiled.

Xu Heng raised his eyebrows, "This is a math problem, not the literary "Book of Changes."

"Forehead……"

He Junfei was ashamed.

Xu Heng, "This question has nothing to do with "Book of Changes". You just need to convert the text into mathematical language."

"6 things, divided into 2 groups, so first count how many there are."

"how many?"

He Junfei knows this, "One is two, and if there are six, it is 2 to the 6th power, which is the total."

"I see...understand!"

Suddenly awakened, He Junfei understood this question.

He smiled slightly at Xu Heng.

But Xu Heng said, "You are only a sophomore in high school, this test paper is not very suitable for you."

He Junfei, "Why do you say that?"

"I think it's because I haven't had much exposure to the question types of the college entrance examination, so on this question, I was stumped by the superficial words."

"Besides, at present, I know what my teacher is teaching, and I have already learned beyond the outline, so it's good to spend some time on these topics by myself?"

"Even Yue Pingting said it, don't you do the same?"

Xu Heng, "But Yue Pingting knows how much she weighs. The questions she does are all what we have learned before or are learning, and you are not the same!"

He Junfei pursed his lips, and pushed his myopia in embarrassment, "So...?"

Xu Heng, "Look at the fill-in-the-blank questions in front of you. There are mistakes, and there are also multiple-choice questions."

"Stop slapping your face and pretending to be fat!"

He Junfei's scalp was numb, "You, how do you know that I did something wrong? You obviously just took the test paper, and you did this test paper before?"

Xu Heng shook his head, "When I was looking at your question just now, I glanced at it and found it."

What the hell! ! !

PS: Thank you for the monthly ticket of [Life is chess, everything is game]!