Xue Chongxun put bamboo poles, protractors, and some carpentry tools on the sand, and asked a few carpenters to do it, and they were busy there. The generals in the army and the civil officials of the yamen next to them saw the boss doing something very strange there, and they all watched curiously. The officials of the engineering room were looking forward to it the most, and they looked carefully with an attitude of curiosity, and they saw how Wei Guogong would measure the height of the cliff...... After tinkering on this sand for a while, you can figure out the geometry of the cliff height in the distance? That's too mysterious!

I saw that Xue Chongxun first set up a wooden board on the ground, and then took the ink line with the iron cone hanging on it, and after a slight flick of the vertical, he left a vertical ink line on the wooden board. In this way, he drew a vertical ink line on the board at the back.

Then a bamboo pole was erected next to each of the two planks, parallel to the two ink lines; Then another bamboo pole was placed horizontally on top of the two bamboo poles.

After tinkering like this for a long time, Xue Chongxun adjusted the angle and let the bamboo pole placed horizontally aim diagonally at the top of the cliff. Then he began to record the angle of the oblique bamboo pole with a carpentry tool, draw it on rice paper, and measure the angle with a protractor...... The angle is about fifty degrees.

At this moment, a horse galloped over and shouted loudly: "Ming Gong, Zhao Si has reported that the distance to the foot of the mountain has been measured." The knight jumped out of the crowd, strode in, and bowed with a piece of rice paper in both hands.

A scribe took the rice paper and brought it back to Xue Chongxun. He took it and looked at it: one hundred and thirteen zhang.

Xue Chongxun was silent, took the angle he measured and the number of Zhao Siju's judgment and left the place, walked to the side under the big umbrella, and said in a big way: "Pen and ink are waiting." ”

"Order!"

Where is this battlefield, it's like a prince and nobleman going out on an outing! The surrounding sergeants were busy waiting for Xue Chongxun, moving the book case, grinding the ink, the scene was really funny.

As soon as Xue Chongxun sat down, an official from the engineering department hurriedly surrounded the scribe who was handing over the rice paper just now and asked, "How long?" ”

"One hundred and thirteen zhang."

The officials hurriedly recorded in their notebooks, while stretching out their heads to see what Xue Chongxun was writing. Their curiosity comes from application, and the new method of measuring height (although rough) is a skill as long as it is learned, which is very beneficial to the career development of engineering officials.

Xue Chongxun looked at the things around him, and while writing and calculating, he explained like a teacher: ""Nine Chapters of Arithmetic" cloud hook three strands, four strings and five, that is, this kind of triangular figure. As long as the shape is similar and the angle is the same, the length of the three lines is proportional ......"

Some officials nodded their heads to record Xue Chongxun's theories, and some were seizing the opportunity to make a big fuss, what Wei Guogong was well-read and well-read, and he was rich in learning, anyway, he would say whatever was disgusting, and Xue Chongxun couldn't wait to jump up and slap him a few times.

Xue Chongxun began to calculate while explaining. Now he has two numbers in his hand, the angle of the right triangle, the parallel distance from the bottom of the mountain, and the two conditions to calculate the height of the cliff without any pressure. As for the value of tg 50 degrees, because there is no function table, it cannot be checked, but there is no pressure: draw a right triangle with an acute angle of 50 degrees, divide the length of the opposite side by the length of the adjacent side, and it will not be calculated?

At this moment, a sergeant came to report: The advance of the Tuyuhun Allied Army was ten miles away from Huangshui, and the Khan King Murong personally led the guards to pay a visit.

The staff on the side said: "Now Tuyuhun is my ally, in order to show the state of Tang etiquette, the lord should welcome the door." ”

Xue Chongxun pondered for a moment and said, "Got it." Then continue to write and draw. Using the method of similar triangles, he finally calculated that the value of 50 degrees of tg is about 1.19.

Then the length from the foot of the mountain is brought in one hundred and thirteen zhang, and the height of the cliff is one hundred and three and a half zhang.

Everyone understands the multiplication operation in the back, and the "Ninety-Nine Song" existed in the Zhou Dynasty, but Xue Chongxun used Arabic numerals to make everyone confused. Xue Chongxun was reluctant to explain the benefits of using columnar formulas to calculate complex multiplication.

Xue Chongxun did not wear official uniforms, nor did he wear armor, and he was wearing his cyan thirty-six kudzu clothes, which was really like a wise man who preached and taught, and he sat among the officials in blue and red robes and talked eloquently, and unconsciously felt that he was spreading the Great Dao like Confucius, Mencius, and all living beings, and he felt very good about himself for a while.

He handed over the result in his hand to the priest Zhao Siju: "The cliff is one hundred and three and a half zhang high, the difference will not be too big, I don't believe that you will use a rope to measure it when you take Shibao City, see if I have miscalculated...... You can use this height to design and build a dirt mountain. ”

This is the number given by the marching commander himself, even if it is wrong, it is not about their division's workshop, and it is a matter of shirking responsibility, where is there anything that Zhao Siju is unwilling, and he replied without hesitation at the moment: "Ming Gong is deeply calculated, is there any reason for not being accurate?" Sure enough, God! Let's visually inspect this cliff, it is almost more than 100 zhang high, God calculates! ”

Xue Chongxun said with a smile: "It's nice to say, I don't know what you think in your heart?" Zhao Siju was suddenly a little embarrassed.

He often speaks without following the rules, making people speechless and not knowing how to answer, which is boring.

Xue Chongxun's fart left the Hu bed, stood up and stretched, his heart was happy, he didn't expect to do math problems so well...... A sense of accomplishment arises. He looked back at the officials and said: "You must not understand the acceleration of the catapult's throwing, the calculation of the parabola, etc., when you need to estimate the height of the throw, just ask me, and I will calculate it for you." ”

All the officials had a five-body expression, and the sycophants shook the sky, "All of them are in the master's clever calculations, and there is no reason to attack the city?" "Zhen Nai Zhuge was born, Kong Ming was reborn......"

Wang Changling indifferently waited for everyone's horses and farts to shoot enough, and then admonished: "The Murong clan of the Tuyuhun Khan King is almost here, does the lord want to change his clothes?" ”

Xue Chongxun looked down at the linen cloth on his body, and looked back at the crowd: "Do I need to change my clothes?" ”

I don't know why, I don't know how to answer.

Xue Chongxun patted Wang Changling's shoulder and said with a smile: "If I weren't the prince of the Tang Dynasty, no matter how fancy the dress was, the King of Khan wouldn't look at it squarely, but am I not the prince of the country?" Look, Chen Bing Lie Ma is magnificent, what does it matter if I wear linen? ”

Everyone immediately laughed, as if they had encountered some great fun, only Xue Chongxun immediately suppressed his smile, and there was no smile at all.

Even if he ordered the soldiers and horses to go out of the camp to meet Murong Xuan, the banner hunting iron armor was like a cloud, and the army was surrounded by the front and back, Xue Chongxun was in a good mood, and almost made a poetic hair, singing "Lao Tzu chats about the madness of youth, leads the yellow on the left, and captures the ...... on the right"

There are white clouds floating in the blue sky, and the sky on this side of the Qinghai-Tibet Plateau is extra clean, as if it has just been washed, the blue sky and green land, the winding water, Xue Chongxun's chest is open, "Drive!" With a shout, he shook the reins, kicked the horse's belly lightly, and ran out along the road on the riverbank. The army hurriedly followed, and for a moment the dust and smoke dispersed, adding a lively atmosphere to the pure and quiet plateau.

From a distance, I saw a group of people coming towards this side, it was Murong Xuan's team, and the scouts had already found out. When the people and horses got closer, they saw that there was a person in a white robe in front of the Tuyuhun crowd, which should be Murong Xuan, the king of Khan. This was the second time Xue Chongxun had seen this Khan King and knew that he was still a young boy.

When the people and horses on both sides were hundreds of paces apart, Xue Chongxun raised his arm to signal everyone to stop, and the opposite side also stopped, only to see that there was a knight behind the white-robed young man carrying a golden animal totem, that thing Xue Chongxun had also seen, and remembered that it was inserted in the king's tent last time.

I can't see the face of the white-robed man clearly, the man has a curtain, and the Tuyuhun people wear that thing, which can cover the wind and sand.

When Xue Chongxun stepped forward, the white-robed man also rode alone to meet him, and the two met in the middle. The white-robed man lifted the curtain on his head, revealing a thin and delicate face, deep eye sockets, and his face really looked a little similar to Murong Yan, worthy of being a sister and brother, who is not Murong Xuan?

Murong Xuan sat quietly on the horse, his pale face seemed to be a little sickly, and he said indifferently: "The Xihai Murong clan should raise 100,000 troops in response to the edict of the Tang Emperor and join forces in Shibao City. "Whether there are really 100,000 people, it's hard to say.

Xue Chongxun looked at Murong Xuan with a smile and said, "Chang'an will know about the loyalty and merits of King Khan, please." ”

Murong Xuan put down the curtain on his head, turned his head slightly, and the people behind him slowly started and followed. At this time, Xue Chongxun saw an acquaintance, Tugu Hun was a big friend, this fat man was really a tragedy, and his wife became Xue Chongxun's lover. When Xue Chongxun saw him, he smiled and said, "Is it okay to say goodbye?" ”

Fu Luhaha smiled: "It's okay, I don't want to meet Wei Guogong again in a few months." ”

"Fate." Xue Chongxun felt relaxed when he talked to this Fu Lu, not as restrained as Murong Xuan, and said in a joking tone, "By the way, didn't the princess come?" ”

Fu Lu said: "I was still shouting to come before, but the king said that this time I would make an alliance with all the tribes, and I brought a woman in the army for fear of making people laugh, so she didn't come." ”

Xue Chongxun's heart was slightly lost.

Murong Xuan and Xue Chongxun marched on horseback, and then said: "Duke Wei Guogong said in his letter that he would give our clan ordnance assistance, hoping to reduce casualties as a result. He said as he looked up at the cliffs in the distance, "This city is difficult......

"What I wrote in my letter is not a lie, not many people died this time." Xue Chongxun said confidently, "Tens of thousands of people die like in the past, even if you win, it will be too tragic." ”

When the group of people approached the Tang army camp stationed by the Huangshui, Xue Chongxun pointed over there and said, "We plan to build a few earthen cities over there, so that we can directly attack the fortress on the cliff with siege weapons." Strength is not a problem, but it takes a lot of manpower to repair the city, which has to borrow the men and horses of the king of Khan...... Sweating is better than bleeding, isn't it? ”G