Harof and Lynn pulled the string straight, with one end pressed under the icicle and the other overlapping the shadow.

When the magic clock reached twelve o'clock, Harof used his hand as a knife and cut the remaining rope very accurately!

"Ruler, bring the ruler quickly!" Harov shouted excitedly. He was in such a hurry to come down that he even forgot to bring the most important ruler.

With his quick eyes and hands, Alok immediately ran back to the airship and handed the ruler to Harof within ten seconds.

The legendary wizard took the ruler solemnly and began to measure in sections as if he was on a pilgrimage.

"Lord Harof, how long is the shadow?" Several accompanying wizards asked with great anticipation.

Harov did not answer immediately, but measured several times before speaking carefully. "It is 1,051 centimeters, or 10.51 meters!"

Those who got the data immediately took out paper and pen to calculate it. Although the great wizards who were qualified to watch the experiment in person on the airship had not systematically studied Olympiad mathematics, they were still clear about the basic geometric calculation methods.

However, this value is not a positive integer. When it comes to decimals, the amount of calculation increases exponentially when squaring and then taking the square root. It took more than five minutes for everyone to use the Pythagorean theorem to calculate that the length of the hypotenuse is approximately 100.55 meters.

After more than two months of Olympiad training, Lydia and Alok were obviously faster than them. They had already started to calculate the angle of the vertex. Substituting it into the triangle formula, sine equals the opposite side divided by the hypotenuse...

"I calculated it, the vertex angle is six degrees!" Lydia, who was the first to calculate it, waved her arms vigorously and shouted loudly.

Harov, who didn't have a pen and paper, got the answer at the same time just by mental arithmetic - Lydia was right, the vertex angle of the triangle and the corresponding geocentric angle were exactly six degrees! The rest was easy, a circle has 360 degrees, the geocentric angle is equivalent to dividing the entire circle into 60 equal parts, each part is 720 kilometers, so the total length is...

"Forty-three thousand two hundred kilometers!" Harov's voice was trembling. He calculated it several times in his mind, fearing that he might make a mistake. After confirming that it was correct, he spoke in a dream. "Forty-three thousand two hundred kilometers! This is the circumference of the planet under our feet!"

Lin En was naturally the one who calculated the fastest. After obtaining the data on the shadow length, the intelligent computer directly presented the answer in his mind.

It seems that this alien planet is slightly larger than the Earth in my previous life.

If he remembered correctly, the circumference of the earth should be 40,750 kilometers, and the two data were very close.

The rest of the wizards also quickly figured out the value, and each of them was so excited that they could hardly contain themselves. Once they knew the circumference, it was only a matter of time to calculate the diameter, radius, and area.

Luo Er, who was standing by, did not participate in the calculations, but instead created a new painting titled "People Measuring the Circumference of Planets Under the Interweaving of the Scorching Sun and the Frost"! The ink-stained quill was waving rapidly on the parchment.

Harof measuring the rope with a ruler, Lynn gazing at the sky as if estimating the angle of the earth's center, Lydia jumping high, and the wizards thinking hard in the back, all come to life on the paper. Against the backdrop of the scorching sun and the floating island, they are extremely impactful and form a strange yet harmonious picture.

Because he knew very well that these two paintings would be remembered forever by the world along with this historic moment!

However, after calming down, Luo Er did not forget another important matter, otherwise some people would not be able to wait any longer.

Thinking of this, Luo Er looked at Harov and asked, "Lord Harov, do you want to send this message to Greenriel now?"

Harov, who was calculating the surface area of ​​the planet, had no time to pay attention and just nodded casually. "Since it has been confirmed, send it!"

…

At the same time, in the city of Greenriel, more than a dozen alchemists were guarding in front of the communication alchemy formation, anxiously waiting for the message from the other side.

But now it is already twelve thirty-seven, and there is still no news, which makes Raphael and others start to doubt whether this operation has failed.

Could it be that Lin En's assumption was actually wrong, and this continent was not a sphere? "Look, there's movement!" A sharp-eyed alchemist immediately noticed the light of the formation, and everyone immediately gathered around.

Since the distance was more than 700 kilometers, the number of magic stones required to transmit information was also a terrifying number, so Roll only transmitted the two most important data: shadow length and vertex angle.

"The shadow length is 10.51 meters, and the vertex angle is 6 degrees..." Raphael looked at the data composed of magic power that kept jumping in the alchemy circle, and shouted excitedly.

With the help of amplifying magic, the news quickly spread throughout Greenriel City, and a strange scene appeared in the entire wizard city. Countless wizards who were eagerly waiting took out parchment and quills and began to calculate at the same time, and even many well-educated civilians joined in.

If one only has the shadow length, one must be proficient in trigonometric functions to calculate the data, which is enough to stump most wizards.

But once you know the data of the vertex angle, it becomes the most basic multiplication and division, and even some ordinary people can calculate it!

"The circumference of the planet is 43,200 kilometers, the diameter is approximately 10,751 kilometers, and the surface area is 594 million square kilometers?" On the crowded streets of Greenrail City, Alex looked at the data he had just calculated and muttered to himself.

He is not a wizard, or rather, due to his limited talent, he does not even have the opportunity to enter a magic school as a wizard apprentice, but he has a strong interest in mathematics.

Before, Alex thought that math was only useful in daily transactions, and at best he could become a tax collector. However, the last issue of Magic Daily opened the door to a new world for him! The wizard named Lin En from the Sea of ​​Mist actually planned to calculate the circumference of the planet under their feet, and he didn't need any magic, just a few simple math formulas!

Ali didn't believe it would be so easy at first, but when these numbers were actually written on paper, there was no doubt in his heart. The shock he felt was hard to calm down. It was as if the world was in his pen! (End of this chapter)