After a while, Yi Chen completed the survey work with the old guy and began to calculate the starting point.

According to the old man, the end of the flower must not be too close to the flower, otherwise there is a danger of being discovered, and it must be at least fifty meters apart.

Yi Chen mentally calculated, measured the distance again, and then found the starting point and prepared to start.

Hu Zhongxian was surprised again, and leaned up and asked, "How did you calculate it, do you have to be so far away?"

"Of course. The corners of Yi Chen's mouth twitched, and he smiled: "I used a math ...... Oh no, an arithmetic formula called the Pythagorean theorem. ”

"Hook...... Hook what?" The old fellow couldn't help but widen his eyes.

"The Pythagorean theorem. Yi Chen repeated, and said: "This explanation may be a bit troublesome, let's start work first, and talk while digging." ”

"Oh......" The old fellow was so confused by what he said that he followed in a daze.

When it comes to digging tunnels, his old man is the main force!

I saw him pull out a silver long sword from the gourd and stab it at the ground!

A silver light shot into the ground, and the seemingly hard black rock silently shattered, and was "eroded" out of a hole that was not too big or small.

This is just a sword, and then, the old guy recites the magic trick, and the silver long sword is divided into two, two, four, eight, eight, and sixteen, and in the blink of an eye, it becomes a neat row!

"Go!" Hu Zhongxian stretched out his hand.

Sixteen flying swords immediately shot out and bombarded the ground in turn!

"Whoosh Whoosh ......"

The silver mangs fell, landing silently, and the originally flat ground was quickly blasted out of a tunnel under the bombardment of this rain of flowers.

Yi Chen stood behind the old guy and kept reminding him to pay attention to the angle, otherwise the finish position might be very different.

"Got it, didn't you say it's a good half-angle?

"No, no, it's exactly 45 degrees at the moment. ”

"Oh, that's good, by the way, what kind of Pythagorean theorem you said, explain it to me. ”

"Good. Yi Chen opened his mouth to a string of mathematical language, bluffing the old guy into a fog, and he didn't know what he was talking about.

"Stop, stop, what is squared, and what does ABC mean?"

"This ......" Yi Chen hesitated for a moment, and simply said from the most basic place.

Fortunately, the square is not a particularly incomprehensible thing, and the old guy will understand it after saying it a few more times, and he can't help but be amazed.

"Grandma's, there is still such a formula, why haven't I heard of it before?"

"Ha, aren't you listening right now? ”

"Well, according to what you say, what we're digging now is a wait...... What are you waiting for? Is it an isosceles right triangle?"

"Yes, this is the easiest to say, because the angle of one of the corners is fixed at 90 degrees, so the length of the two right-angled sides must be the same, and you don't even need to count. ”

"What if the angle is different? For example, if I want to dig a 30-degree one, how do I calculate it?"

"It's a bit more cumbersome because we only know the angle and the length of one of the sides, so we use trigonometric functions. ”

"Three...... Trigonometry? What the hell is that?" old guys, everybody's going crazy.

"This ......" Yi Chen is also the first two big.

If you want to talk about the Pythagorean theorem, he still has the patience to explain it, after all, it is not a difficult thing, as long as it is a person with a normal IQ, it can be understood.

But trigonometric functions......

it!

Although trigonometry is not too difficult, it is generally learned in middle and high school, but don't forget the identity of the old guy.

For a man with almost no mathematical background, do you want to explain to him what trigonometry is......?

In the end, the matter was settled.

Yi Chen said a little casually, and the old guy was dizzy when he heard it, so he simply gave up.

According to his original words: "I'm old, my learning ability is relatively poor, I really can't help it, your kid is so good at arithmetic, I will leave it to you if there is such a situation in the future, anyway, yours is mine." ”

"Dig a hole, dig a hole. Yi Chen grinned and didn't answer.

After about half an hour, Hu Zhongxian finally dug the hole in the ground, he asked Yi Chen to open the eye of the spirit rhino and scan, and found that as long as he dug another three or five meters, he could break through the wall.

The depth here was already one or two hundred meters above the ground, which was considered a very deep cave, and Yi Chen felt very difficult to breathe as soon as he stayed in it for a long time.

"Okay, no more digging. The old guy put away his sword and said with a smile: "Just leave such a little bit here so as not to arouse suspicion, and when the time comes, you will have to go out, which is a matter of a sword." ”

"I'll see. Yi Chen looked up a few times, nodded and said, "Yes, this place is almost fifty meters away from the flowers of the Bright Night Crystal Ice, which is exactly in line with the warning distance you said." ”

"Well, then that's all for today, let's go out first, and come back tomorrow to see the situation, if it's suitable, just do it, if it's not suitable, it's okay the day after tomorrow." ”

“OK。 When Yi Chen heard this, he hurriedly turned around and ran out.

He's meowing, it's really suffocating here! It doesn't matter if an old guy doesn't have a physical body, he's a living person!

Running all the way to the ground, Yi Chen finally breathed fresh air, and he felt so refreshed.

He began to return the way he came, chatting and laughing with the old fellows on the way, discussing all the details of tomorrow's plan of action.

In any case, tonight's group has solved a lot of problems and accumulated a lot of experience, which will undoubtedly be of great help to tomorrow's action.

By the time Yi Chen rushed back to the Liangqi House, almost three hours had passed.

During this period, the silver-armored man Lao Ma has never come.

After all, last night he had already learned that the little prodigy's cultivation was good, enough to withstand the scorching cold of this first-layer cultivation room, so he didn't bother to bother.

Besides, Feng Zhangshu had already told him that this was a critical period, and the academy needed to fight for such a person to get started, so no matter what request he made now, as long as it was not too angry and resentful, he had to try his best to meet him.

Enter the two Qi houses to cultivate...... What kind of request is that? It's not too much, let alone angry.

As long as the little prodigy is willing, it's best to stay in it all the time and not come out. ~

The longer this drags on, the less patience other competitors will have, and eventually they will automatically give up.

To sum up, the silver-armored man now wishes that the door of this cultivation room would never open, so how could he take the initiative to urge?~

Yi Chen didn't know about this change, and it was last night.

Liangqi House is such a good place, as long as you come, you must not waste a single thing.

Since the people outside didn't move, then of course he inside wouldn't look at the time and leave consciously. ~

What, you ask about quality?

I'm sorry, what is the quality?Is it delicious?How much is a pound?~

In the end, Yi Chen still had the cheekiness to stay, removed the illusion charm and sentry charm, and continued to meditate and practice.

Originally, he planned to cultivate for a short while, as soon as someone came to call, he would go out immediately, and he would never grind.

However, for a whole night, not half a person came to shout.

Yi Chen, this guy, has also been immersed in the fun of the three exercises of the initiate, and he has forgotten the time.

It wasn't until Qingming that he was woken up by Huzhong Xian, and he habitually asked, "What time is it?"

"It's time to go. The old guy smiled.

"What??" Yi Chen was dumbfounded, "This ...... How...... Why didn't you call me earlier, senior!?"

"Hey, you kid practiced all night, and you blamed me if you didn't remember the time? ”

"I ......" Yi Chen's hatred!

He can imagine that he didn't return all night last night, and he didn't have a letter, Qingyun must be in a hurry.

In the morning, Chao Yan might also go to the inn for a visit, and then happened to meet the crying Qingyun......

Oh－shit！

"What's wrong?" Hu Zhongxian has been observing his face, and when he saw someone's expression, he couldn't help frowning and said: "I thought you would be very happy, you know, no one came to call you last night, you practiced all night in this cultivation room in vain, how much money you make, what else is not satisfied?"

"Satisfied...... I'm satisfied. ”

"Then what are you doing with a bitter face? ”

Yi Chen had to squeeze out a smile.

"Oh, be happy. The old guy patted him on the shoulder and said with a smile: "Last night's practice was of great benefit to you, originally you were a congenital one-level cultivator, but now you are about to enter the second one." What's more: cultivating here does not require medicinal materials, and it can also effectively consolidate your current realm. Can't you feel it yourself?"

"Well, there are feelings. Speaking of this, Yi Chen suddenly came back to his senses, "The hot and cold Erqi here is really a good thing, how much is needed, just use the spiritual sense to peel it off, and the absorption is also fast, unlike medicinal materials, the amount is not easy to control, and it must be refined repeatedly." ”

"Yes, otherwise why would Dongping Academy have to work so hard to build this thing?" the old guy smiled slightly, and said: "Okay, it's almost time, you should go out for a walk, don't sit all the time, it's not good for your health." ”

"Hmm. Yi Chen nodded, got up and left the cultivation room, and walked outside.

When he went out, he ran into the silver-armored man again, and couldn't help but greet him with a smile: "Brother Ma, it's early." ”

"Aha, little prodigy, you're finally willing to break through. ~" As soon as Lao Ma saw him, he immediately smiled, "What, you have practiced all night, you must be hungry now, right?" Feng Zhangshu has already come just now, saying that if you finish your cultivation, please go directly to the dormitory on the west side of the academy, he has arranged a room for you, you will be picked up by someone when you go, and after you finish washing, you can go to the canteen to find Master Fan, and a sumptuous meal will be waiting for you at any time. ”

"Okay, thank you. Yi Chen bowed to him, turned around and hurried away.

When he was far away, the silver-armored man immediately turned around and stretched out his palm, laughing and said: "Hahaha, I said it, this kid will definitely be able to hold out for one night, who else is not convinced now? Hmph, give me the money for my mother, I am willing to lose the bet, hurry up!~"