Why is Pythagorean theorem the first mathematical theorem discovered by human beings? When I studied the Pythagorean theorem, I felt that the discovery of this theorem was not simple. Why do many countries say that the Pythagorean theorem is the earliest mathematical theorem they know. Is this accidental or

Why is Pythagorean theorem the first mathematical theorem discovered by human beings? When I studied the Pythagorean theorem, I felt that the discovery of this theorem was not simple. Why do many countries say that the Pythagorean theorem is the earliest mathematical theorem they know. Is this accidental or

Sorry, I don't know much about mathematics
I can only say from the feeling, first of all, the Pythagorean theorem has a long history, which is traditionally believed to be proved by Pythagoras of ancient Greece. Secondly, it seems simple, but it has great use and contains a harmonious aesthetic level. Maybe this is why many countries say that the Pythagorean theorem is the earliest mathematical theorem they know

A geometric problem about Pythagorean theorem! It is known that in the right triangle ABC, the angle c is equal to 90 degrees, D is the midpoint of AB, and DM is perpendicular to DN, Am = 6, BN = 8, find Mn (hint: prove that the sum of squares of AM and BN is equal to the square of Mn)

MN=10
prove:
Extend MD to e, intercept de = MD, connect EB
It is proved that the triangle AMD is equal to the triangle bed, so EB = 6
Connecting en, there's Pythagorean theorem, so en = 10
Because nd is the vertical bisector of me, Mn = en
That is, Mn = 10

Some junior high school geometry problems about Pythagorean theorem 1. The main project of the new residential building has been completed. It is required to stick ceramic tiles on the external surface of the building. The area of the external surface of the building is 5000 square meters. (1) what is the functional relationship between the number of tiles N and the area s of each tile (2) Use gray, white, blue three kinds of color ceramic tile, the area of each tile is 80 square centimeter, the proportion of gray, white and blue tile is 2:2:1, how many pieces of three kinds of ceramic tile are needed? 2. In △ ABC, ∠ C = 90 degrees, ab = 10 (1) ∠ a = 30 degrees, calculate BC, AC (accurate 0.01) (2) ∠ a = 45 degrees, calculate BC, AC (accurate 0.01) 3. In △ ABC, ∠ C = 90 degrees, AC = 2.1cm, BC = 2.8cm (1) Find the area of △ ABC; (2) Find the hypotenuse ab; (3) Seeking high CD 4. There is a semicircle above the gate of a loading and unloading company (the width of the gate is 2M and the height of the gate is 2.3m (excluding the upper semicircle). If a truck is full of goods, it is 1.6m wide and 2.6m high. Can the truck pass through the gate (the distance between the upper end of the truck and the door is not less than 0.2m)

1、
（1）NS=5000
(2) The total number of tiles required is: n = 5000 × 10000 △ 80 = 5000 × 125
The required fast numbers of three kinds of gray, white and blue tiles are 2n / 5, 2n / 5 and N / 5 respectively
Yes: 250000250000125000
2、
（1）BC=ABsin30°=10/2=5.00
AC=BCsin60°=5.00*1.732=8.66
(2) BC=ABsin45°=7.07
AC=BC=7.07
3、
(1) Area = AC * BC / 2 = 2.94
(2) AB = sum of squares of AC and BC under root sign = 3.5
（3）CD=AC*BC/AB=1.68
4、
If you can't draw a picture, you can see it step by step
First of all, the radius of the semicircle is 1m. The height of the car is 2.6m, and the upper end of the car is 0.3m above the diameter of the semicircle (the upper edge of the box is the diameter of the semicircle). On the vertical radius, find such a point a 0.3m away from the center of the circle. Then make a horizontal line through this point and intersect the circle at point B. in this way, the triangle formed by the center of the circle O can be calculated as AB > 0.9 by using the Pythagorean theorem, In this way, the distance from the top of the car to the horizontal ends is > 1.8, and of course, it is > 1.6. You also find that the distance between the top of the car and the highest point of the door is 0.7m > 0.2m
So, the car can pass

In an extracurricular practice activity, students need to measure the distance between two pavilions A and B on both sides of the artificial lake in a park. Now AC = 30m, BC = 70m, ∠ cab = 120 °, please calculate the distance between two pavilions A and B

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Eight year geometric Pythagorean theorem It is known that in △ ABC, ad is the midline on the edge of BC, ad = AC = 1, ab = radical 5, and it is proved that ad ⊥ AC, ab = radical 5

Since the square of AC plus the square of EC is equal to the square of CE, AB is equal to CE, AE is equal to 2ad

Several geometric mathematical problems (Pythagorean theorem) 1. Ad = radical 6, DC = 5 - radical 3, BC = 6, ∠ ADC = 135 °, DCB = 120 °, find the length of ab 2. It is found that the distance between two points of AF can be obtained by ∠ B = ∠ C = ∠ d = ∠ e = 90 ° and ab = CD = 3, BC = 4, de = EF = 2 3. Δ ABC is an isosceles right triangle, ab = AC, D is the midpoint of the hypotenuse BC, e and F are the points on the sides of AB and AC respectively, and De is vertical DF. If be = 12 and CF = 5, calculate the area of △ def

1. AB = 3 + 8 root sign 3
2. AF = 2 root sign 2

Geometric mathematics problems in grade 2 (Pythagorean theorem) 1. In RT △ ABC, the opposite sides of ∠ C = 90 °, a, ∠ B and ∠ C are a, B, C respectively, and a + B = 2 √ 3, C = 2. Calculate the area of △ ABC 2. As shown in the figure, fold the rectangle ABCD along the straight line AE, and the vertex d just falls at point F on the edge of BC. If CF = 3cm and ab = 8cm are known, what is the area of shadow part in the figure? (if the picture can't be sent, please send me a chat)

It is proved by Pythagorean theorem and trigonometric function
Draw the words, 50 meters for the slope, 30 meters and 40 meters for the right angle side
The angle between the 40m side and 50m side is calculated and expressed by inverse trigonometric function. Then the angle between the 40m side and 50m side is subtracted by 45 degrees (because it is to the southwest)
I figured it was 45 arc Tan (3 / 4) degrees east by North

There is a triangular open space in the campus. Now we are going to plant turf on this open space to beautify the environment. We have measured its three side lengths as 13 meters, 14 meters and 15 meters respectively. If this kind of turf costs 120 yuan per square meter, how much is the minimum cost of purchasing this kind of turf? How to get the length of the high 12 students

Make the height of the side with the side length of 14
According to Pythagorean theorem, the length of this high is 12
So the area of the triangle is 1 / 2 * 14 * 12 = 84
The expenditure needed is 120 * 84 = 10080 yuan

Who wrote nine chapters of arithmetic?

There are different opinions about when the book was finished. Most people think that the author of Jiuzhang arithmetic is unknown between the end of Western Han Dynasty and the beginning of Eastern Han Dynasty, about the first century AD

Problems in nine chapters arithmetic Pu RI Sheng 3 Chi, Guan RI Sheng 1 chi, Pu RI Sheng from half, Guan RI Sheng from double, ask how long Pu and Guan are equal?

By the end of the second day, the length of cattail was 3 + 1.5 = 4.5, the length of Guan was 1 + 2 = 3, 4.5 > 3, less than 4.5 - 3 = 1.5 feet; by the end of the third day, the length of Pu was 4.5 + 0.75 = 5.25, the length of Guan was 3 + 4 = 7, 5.25 < 7, and the remaining 7-5.25 = 1.75 feet