Early in the morning of that day, many students who had gotten up early and studied hard discovered that the knowledgeable and talented officials of the Imperial College, represented by Luo Siye, were walking out from the northwest corner in a panic, and their steps were so fast that it seemed as if there was a ghost chasing them from behind.
The obedient students hurriedly stood by the road to salute and greet their teachers, but Luo Siye and others just nodded slightly and did not stop at all, as if any stop would lead to something unexpected.
Faced with this strange sight, some curious people quietly followed the way they came, and then found the old lecture hall with the door wide open. However, what made them even more surprised than the door wide open was the evil star standing at the lecture hall door, staring at a pile of lanterns and candles on the ground with a complicated expression.
That was Xu Heizi, the supervisor of the Shengqian Hall. He had a vicious heart and even more vicious hands. Every student would feel their buttocks tighten when they saw him!
So, a few students who came to watch the fun tiptoed back, and then they heard Xu Heizi's signature cold voice: "Lu Zhu, since you can recite the Nine Chapters of Mathematical Classics, let me ask you, what does Yangma mean? What does Biejian mean?"
After this was said, the students who thought that Xu Heizi was questioning them looked at each other in bewilderment. One of them vaguely remembered where he had seen these two words, and frowned for a moment, thinking hard, racking his brains to recall the source. Soon, he got the answer.
"It seems that Xu Jiancheng has never read the Nine Chapters on the Mathematical Classic."
When he said this, Lu Sanlang was beaming with joy, and he was extremely proud. He had always been criticized by others for being unlearned, and this was the first time he said that others didn't read books! It was not until he heard Zhang Shou cough behind him that he quickly put away his intention to show off.
"Let me explain it simply. If there is a cube with a width of one foot and a height of one foot, and you cut it diagonally from top to bottom, you will get two trenches. If you cut one of the trenches diagonally along the bottom line and the top angle, you will get one Yangma and the other Biebin. The size of Yangma accounts for two-thirds of the entire trench, and the size of Biebin accounts for one-third of the entire trench."
Lu Sanlang looked at Xu Heizi, whose face was calm but whose eyes clearly revealed the word "bewilderment", and he couldn't help but add proudly.
"My little master's annotation on the Nine Chapters on the Mathematical Art is that Yangma is a four-sided pyramid with a rectangular base, and Biebin is a three-sided pyramid with two right-angled triangles. The size is the volume. As for rectangles and right-angled triangles, three-sided pyramids and four-sided pyramids, what do they mean by volume? Well, my master Ge will compile a terminology manual later, otherwise I think you won't understand it."
Without waiting for Lu Sanlang to explain, Xu Heizi turned around and left with a dark complexion. The students who were looking out from behind to watch the fun had no time to dodge, so they could only smile and call out "Xu Jiancheng" and then watch him leave in fear.
As for Lu Sanlang, he was grinning happily when he was suddenly hit on the head.
"You feel like showing off, don't you? Don't forget what you said before. It's true that you have read the Nine Chapters on the Mathematical Art, but if I hadn't explained the chapter on business skills in detail, you would have been confused! Instead of showing off in front of an outsider, why don't you show off to Teacher Ge?"