How do you do this?

Ye Qingqing encountered a roadblock right at the beginning: she couldn't solve a solid geometry problem.

Actually, she didn't understand it at all. She only understood that it was an irregular three-dimensional shape, which looked like a cuboid containing a sphere and a triangular prism. The question was to prove that two lines were of equal length.

Um... the person who set this question must be mentally ill, case closed!

If the lengths are different, just measure them with a ruler, why bother with all that trouble to verify?

I really don't understand the point of learning these problems.

She just wanted to study medicine, so she accepted her fate with organic chemistry. But what use are these strange and unusual diagrams anyway?

What disease is it related to?

Ye Qingqing scratched her head helplessly, then simply took out a ruler to measure. And just like that, she discovered a new world!

"This question is wrong. The lengths are clearly different, yet I'm asked to verify it. Is the person who set this question out of their mind?"

Ye Qingqing pointed at the diagram and exclaimed, measuring it again as she did so, "Look, this line is 2.1 centimeters, and this one is 2.2 centimeters. They're only 1 millimeter apart! A small difference can lead to a huge error!"

That's so sloppy!

"You're getting stuck on this!" Lu Moxin felt really frustrated.

He's been using all his energy on crooked and unethical methods; no wonder his grades are among the worst.

Ye Qingqing wouldn't have it, and said confidently, "This is my rigorous learning attitude. One millimeter is one thousand micrometers, one million nanometers, one hundred million picometers. What a huge oversight! If we made a mistake of one millimeter when launching a rocket, the rocket that was supposed to go to the moon might end up on Mars instead..."

"It's just a printing error, why are you bringing up the moon and Mars?"

Lu Moxin felt even more frustrated. It was true that he was too smart to use his intelligence in the right way. He remembered the conversion units such as micrometers, nanometers, and picometers very clearly, but he just wouldn't study properly and instead gave him so many twisted arguments!

Ye Qingqing sniffed and said softly, "Anyway, it's wrong. I don't think there's any need to verify this question anymore!"

"Who said they were going to study hard yesterday?" Lu Mo asked sternly.

She's in her final year of high school now. If she doesn't study hard, she won't even get into the lowest-ranked vocational college, let alone medical school. And with her carefree attitude towards studying, even if she repeats a year, she probably still won't get in.

Although studying is not a necessary path to success, this girl has such a good talent for medicine, it would be a pity if she didn't go to medical school. Lu Mo firmly believes that after Ye Qingqing goes to medical school for formal training, she will definitely achieve even greater success!

He had to strictly supervise the girl's studies and try to turn things around in the final year!

Ye Qingqing trembled, lowered her head guiltily, and said in a muffled voice, "I'll do it now, I didn't say I wouldn't!"

Lu Mo smiled with satisfaction. After looking at the question, he added a line to the figure with a pencil. "Geometry can add auxiliary lines. If we add a line here, won't we have two more equilateral triangles? According to the principle that the side lengths of equilateral triangles are equal, these two lines must be equal."

This question is actually very simple; it can be considered an introductory question in solid geometry. It's surprising that Ye Qingqing, a second-year high school student, couldn't do such a simple question from a first-year high school student. You can imagine how bad her grades are!

Lu Mo felt the burden on his shoulders grow much heavier. His left shoulder was like Mount Tai, and his right shoulder was like Mount Hua. The task was arduous and the road ahead was long!

Ye Qingqing's eyes widened, and she was completely confused. Solid geometry was just too abstract. Why couldn't she see that there were two equilateral triangles?

What's the difference between adding this line and not adding it?