Jian Zhaoxing

Chapter 195 Lu Huai's Geometry! The Brahmagupta Model!
"What method?" Lin Yangyang's eyes lit up.

Lu Huai said, "What we need to do now is simply find another hidden location, which will be difficult to find in a short time."

"But I've been thinking that this place only needs to meet two conditions."

Upon hearing this, everyone else looked puzzled, but Lin Zhiqing seemed thoughtful.

"Which two conditions?" Jiang Liuyun asked excitedly.

“Things that are square all have four corners.” Lu Huai pointed to the houses not far away: “Just like these houses in front of us, they all have four corners.”

“That’s right.” Lin Shi’an nodded.

“I once encountered a dispute among the common people,” Lu Huai said quickly. “A merchant died and left a shop to his two sons.”

"That shop faces south and has an excellent location."

"The two sons originally wanted to split the shops in half and reopen them, but the businessman had consulted a fortune teller who said that if the shops were separated, they could not both face due south, otherwise it would affect the feng shui and thus the business."

"If that's the case, why not just hang one on the south side and one on the north side?" Lu Nanyue was a little confused.

Lin Zhiqing shook his head: "If that's the case, the person who opened the shop on the north side will definitely not be happy."

“That’s right.” Lu Huai continued, “My two sons couldn’t resolve their dispute, and it escalated to the point where the government was involved. The Ministry of Revenue sent me to investigate.”

“I proposed a solution: divide the shop in two and then renovate it.”

"The east corner of one shop and the west corner of another are adjacent to each other, while the other three corners are unrelated. The door of one shop faces southwest, and the door of the other faces southeast."

"Two rooms side by side?" Jiang Liuyun scratched his head, clearly not expecting such a place to exist.

The others, however, were completely baffled.

Wait a minute... Lin Zhiqing frowned.

The "corner" in Luhuai dialect is the concept of "corner" in her understanding.

What Lu Huai said can be translated as: if you take one right angle from each of two cubes and connect them, then there will be a common vertex between the two right angles.

Extending vertically along the common vertex, two triangles can be formed, one above the other.

She had heard her teacher mention this geometric model in class.

What was it called again?

Lin Zhiqing pinched her chin, and thought it was something like "Po-something"?

She silently repeated it to herself several times, and finally remembered!
The Brahmagupta model!
If the name weren't so complicated, Lin Zhiqing would never have remembered it after hearing it only once.

She went over it in her mind again, and yes, it was the Brahmagupta model!

Upon realizing this, Lin Zhiqing instantly understood Lu Huai's meaning.

I remember now, I remember everything.

Her teacher once gave an example to prove that mathematics is ubiquitous and very simple in life.

In order to hit a target, a sniper often has to consider factors such as the height at which he raises his gun, terrain, wind speed, and the trajectory of the object.

Among them, the Brahmagupta model is often taken into account by snipers when considering terrain.

This type of terrain can serve as good cover, ensuring that snipers remain undetected.

At the same time, once the location of the common vertex is determined, snipers can quickly make corresponding judgments regardless of where the target moves, thus improving the hit rate.

How similar this is to their current situation!
I'm grateful to my past self who never drifted off to sleep during class.

"I remember a place with a house like this." Lin Zhiqing glanced at Lu Huai:
“There are two houses not far from the entrance of the market arranged like this. I observed them when we went to the execution ground last time.”

“What we’re thinking about is a place,” Lu Huai said, a smile playing on his lips.

In the past, when he talked about these issues, neither his sister nor his father understood.

But Lin Zhiqing could quickly understand what he meant.

This instant understanding filled Lu Huai with a strong sense of excitement.

"We should hurry over there, otherwise Liu Mang will be here soon. If we miss him, everything we've done today will have been for nothing." Lin Zhiqing looked at the others.

The others didn't understand the cryptic conversation, but seeing the urgency of the situation, they didn't have time to ask any more questions. "What are you all standing there for? Let's go!" Jiang Liuyun picked up his bow and arrow and was about to move forward.

But Lin Zhiqing grabbed him and said, "You're already injured, you can't move around anymore. Besides, you might have to go to the battlefield in the future, and it would be troublesome if you had any lingering injuries."

"Qing'er, I missed just now. No matter what, I must atone for my mistake!" He clenched his fist.

Everyone could see that he was under a lot of pressure.

Lu Nanyue glanced at Lin Zhiqing, then looked closely at Jiang Liuyun's shoulder before shaking her head slightly: "Young Master Jiang, if you insist on moving around, this arm may never be able to be lifted again."

“But…” Jiang Liuyun pursed his lips, still trying to hold on.

Lu Nanyue interrupted him, saying, "I'm a doctor, and I know the condition of your shoulder better than you do yourself."

"Brother Jiang, you should rest well. If something happens to you, how will we explain it to Uncle Jiang?" Lin Shi'an earnestly advised.

“Exactly, exactly.” Lin Yangyang chimed in casually, “Don’t worry, with me here, you won’t miss again.”

Jiang Liuyun's expression immediately turned somewhat dejected.

"Cough cough." Lin Shi'an pulled Lin Yangyang back.

"Don't overthink it. Everyone makes mistakes sometimes. Fortunately, there's still a chance to make amends. The longer we delay, the less chance we have," Lin Zhiqing comforted her.

Hearing this, Jiang Liuyun managed a smile: "Qing'er, I understand, you can go."

Lin Zhiqing smiled slightly and then looked at Lin Shi'an: "Cousin, you and Nan Yue stay here to take care of the young master."

Lin Shi'an and Lu Nanyue nodded in unison.

After giving his instructions, Lin Zhiqing picked up the child and walked to Lin Yangyang's side.

Lu Huai patted Jiang Liuyun's unaffected shoulder and walked over.

Then, as if remembering something, Lin Zhiqing looked at Lu Nanyue: "Nanyue, where did this child come from?"

“At the time, no one was willing to lend the child, so I contacted the child’s parents. I had saved their lives before, which is why it took some time.”

Lin Zhiqing nodded and didn't ask any more questions.

At the same time, Lin Yangyang was about to reach for the bow and arrows when Lin Zhiqing stopped her:

"Cousin, we don't need this anymore, let's go."

Lin Yangyang decisively gave up the bow and arrow.

The group quickly found horses and headed towards the entrance of the market.

To Lin Zhiqing's surprise, Lu Huai, who looked like a weak scholar, was surprisingly fast on horseback.

But then she thought about it again, and realized that children of powerful and wealthy families like Lu Huai were raised by specialists from a young age.

Lu Huai was skilled in numerology, but that doesn't mean he only knew numerology.

Everyone has some unique skill or talent.

Putting those thoughts aside, Lin Zhiqing hugged Lin Yangyang tightly around the waist.

After exerting all their strength, the group finally overtook Liu Mang.

After reaching one side of the two rooms in one go, Lin Zhiqing handed the child over to Lu Huai.

The two dismounted and discussed the matter. Lu Huai's expression changed from confusion to sudden understanding.

Then, he carried the child into the gap between the two rooms, and soon disappeared from sight.

After Lin Zhiqing remounted his horse and walked about a hundred paces behind the crevice with Lin Yangyang, the two of them kept their eyes fixed on the crevice, without being distracted.

"Cousin, when you're done, aim at the gap between the two rooms, and make sure you don't miss!" Lin Zhiqing instructed.

"Don't worry, Fourth Uncle's life is still in our hands, I won't be careless." Lin Yangyang waved her hand.

“However…” she frowned, “without a bow and arrows, how am I supposed to fight Liu Mang?”

"Use this." Lin Zhiqing took something out of his waist and then opened his palm.

A slingshot lay quietly in her hand.