Why is a circle 360 degrees, why is a circumference 360 degrees

In ancient civilizations, human beings attributed many unexplained natural phenomena to "providence". From the judgment and prediction of "providence", astrology developed, and also promoted the development of early astronomy. After a long period of astronomical observation with the naked eye, the ancients finally made a major discovery - the trajectory of each star is a circular ......Their position in the night sky shifts slightly each day compared to the day before, until one cycle, a year later, when they return to their original positions.

Have you ever discovered now that there is a subtle relationship between having 365 days in a year and a circle having 360 degrees?

One theory is that the ancient Babylonians inherited the sage-based notation of the Sumerians of the third century BC on the plains of Mesopotamia, dividing the year into 360 days (12 months, 30 days per month), so that for the reasons described above, a circle could also be divided into 360 equal parts, each of which is "one degree". More than 300 years after the Babylonian Empire was wiped out by the Persians, the Greek astronomers Aristarchus and Hipparchus re-systematically summarized the achievements of the Babylonians in astronomy, the concepts of "constellations" and "celestial spheres" appeared for the first time, the sexagesimal system continued to be carried forward, the basis of celestial division was established, and the statement that "a circle has 360 degrees" began to become a scientific standard and gradually been affirmed by people.

The reasons why <> circle is 360 degrees are as follows: 1. First of all, it is easy to divide the circumference of the sixth, because the chord length of the sixths is equal to the radius, so the evenly divided degree of cherry blossom should be divisible by 6. In the same way, right angles are the most used in architecture, and a circumference is 4 right angles, so the degree of equal division should also be divisible by 4.

And 4 and 6 are both factors of 360. 2. It contains the most factors, integers from 2 to 10, except for paragraph 7, which are all factors of 360. That is, 360 is divisible by 2, 3, 4, 5, 6, 8, 9, 10.

If you must include 7, the most slippery number is 2520, this number is too large, and the situation of seventh division is rare, so the final determination is that in addition, the concept of time is determined by the rotation and revolution period of the earth and the moon, and the rotation of the celestial body is 360 degrees, for the convenience of the time unit, we should also try to choose 360 as many as possible to choose the whole number with many factors. It is no coincidence that 12 months of the year, 30 days of the month, 24 hours of the day, 60 minutes of the hour, these numbers are all factors of 360.

The reason why the circumference is prescribed as 360 degrees is that the ancient Egyptians believed that 360 days was a year (although there were some discrepancies with the reality), and the time of the year was just to observe the ecliptic plane.

Cycle for a week, and the ancients used a simple philosophical unity of view, believing that 360 is a constant in the world, so later in astronomical observation and circumference measurement, 360 was used as the degree of circumference.

The most essential, primitive angle is obviously from the circumferential angle.

Started! Then, the circumferential angle is exactly the angle corresponding to the entire circumference! The ancient Egyptians moved from the daily silver of the sun to the rising and setting cycles of the Nile and every other year.

The meaning of "year" is realized at intervals when the water floods regularly. This, coupled with the fact that the Egyptians had developed astronomy, allowed them to track Sirius very well.

so they set the year at 360 days (of course, such an error is large. But that's for later).Based on this, the angle of the ------ circumference of a circumference in the simplest period is defined as 360 degrees.

A circle represents an infinite polygon.

And an angle of a polygon wants to become a circle, when the inner angle of this angle is less than 180°, the inner angle needs to increase, and when the inner angle is greater than 180°, the inner angle needs to decrease, so it can be seen that at each point on the circumference of a circle, the inner angle is 180° and the outer angle is 180°, and a circle is composed of countless points, so the inner angle of the circle is infinite, and the outer angle is infinite. The formula for the sum of the inner angles of a polygon is [n minus 2 times 180], then when a polygon has its sides infinite, the sum of its internal angles is infinite, and the circle can be regarded as a regular polygon of infinite polygons, so the sum of the inner angles of the circle is infinite.

You can draw a maximum regular hexagon in the circle, and draw six line segments to the vertices of the hexagon with the center of the circle, and six regular triangles are formed in the hexagon, because the degree of one vertex of the regular triangle is 60 degrees, so the degree of the circumference of the center of the circle is 60*6=360 degrees.

Fold it symmetrically in half with a piece of paper, and the center of the circle is exactly 4 right angles, so the inner angle of the circle is 360 degrees.

Because of mathematical reasons, the composite number can be divided by any number of 1 10, and all positive integer states within 360 have the most factors in the air, and because of the blind length of a year, people know through the observation of natural phenomena that there are 365 or 366 days in a year, which prompts the universe to be defined as 360 degrees, and the algorithm of the ancient Bilong uses a decimal 60 number system to evolve, and a circumference is defined as 360 degrees by the posture disturbance.

This is calculated according to the principles of mathematics, 360 degrees is a circle, there is a problem of angles, there are some mathematical theories.

Because it is artificially prescribed, because the circumference is a circle, and the end point is connected to the beginning, it is specified to be more than 360.

Since ancient times, the sages of the first collapse calculated that the circumference of the circle is c = d, which is approximately equal to. By using the infinite accurate calculation of the circle inscribed regular polygon, it is found that the circumference of the circle inscribed regular polygon is s=2nr*sin( n),n 3, so when n=, s=c, then d=2nr*sin( n), take the value approximately equal to calculate =, this c value represents the arc length of this table, according to the conversion formula of the roundness and angle of the arc = r, the circumference of the circle =2 r r=2 =2*180=360 degrees.

The ball is made up of an infinite number of circles, so it is said that the circumference of all circles is 360 degrees.

All the circumferential angles of the sphere are 360 degrees.

The degree of the ball is only matched by the wild, and the spine is spherical.

denotes that it is equal to the sphere area radius

Spherical area = 4 r and sphericity = 4 r r = 4 can also be referred to as solid angles.

It is equal to the area of a ball with a vertex as the center of the circle and a radius per unit length, and the part truncated by the solid corner.

Theorem. In a flat rolling plane, the closed curve formed by rotating around a point and at a distance of a certain length is called a circle, and the 360 degrees of the circle is a theorem. In a plane, a circle is a set of points whose distance to a fixed point is equal to a fixed length, called a circle.

The circle has an infinite number of streaks based on axes of symmetry, and the axis of symmetry passes through the center of the circle.