What is the law of circumference, the law of pi

More than 3,000 years ago, during the Zhou Dynasty, it was believed that the ratio of circumference to diameter was three to one, that is, pi at that time was equal to three. However, it was Liu Hui of the Wei and Jin dynasties (c. 263 AD) who really found the exact rate of pi, and the method he used was called circumcisionHe discovered:

As the number of sides of the circle becomes more and more inscribed with a regular polygon, the perimeter of the polygon will be closer and closer to the circumference of the circle, and the area of the polygon will be closer and closer to the area of the circle. Therefore, Liu Hui used the relationship between the area of the regular polygon and the area of the circle, starting from the regular hexagon, and gradually doubled the number of sides: regular 12 laterals, regular 24 sides, regular 48 sides, and regular 96 sides.

On the basis of Liu Hui's research, Zu Chongzhi further developed, and after a long and tedious calculation, he calculated until the circle was connected with a regular 24576 polygon, and came to a conclusion: the value of pi is between and ; At the same time, he also found the approximate rate of pi: 22 7, the density rate:

355∕113.In order to find the seventh decimal place of pi, Zu Chongzhi calculated the side length of the regular hexagon to 28,672 decimal places, which is a great achievement. There are three points worth noting, he did it himself, because you can't find the first to eighth decimal places after the square, and at the same time, there is another person to find the ninth to sixteenth places

The abacus currently used did not appear until the twelfth century, and there was no abacus in Zu Chongzhi's time, which shows the hardships of opening the square.

Pi is pie. Infinite does not loop decimals. Used to calculate the circumference of a circle and the area of a circle.

The law of circumferential angles is as follows:

The circumferential angle theorem states that the circumferential angle of an arc is equal to one and a half of the central angle of the circle. This theorem is called the circumferential angle theorem. This theorem reflects the relationship between the circumferential angle and the central angle of the circle.

Proof: It is known that in O, BOC and the circumferential angle BAC are the same as the arc BC, and the eggplant year is verified: BOC=2 BAC.

oa=oc；bac= aco (equilateral equilateral).

Theorem corollary: 1. The circumferential angle of an arc is equal to half the age of the central angle of the circle it opposes.

2. The degree of circumference is equal to half of the radian of which it is opposed.

3. In the same circle or equal circle, the circumferential angle of the same arc or equal arc is equal; The arcs opposite the circumferential angles that are equal are also equal.

4. The circumferential angle of the semicircle (diameter) is a right angle.

The circumferential angle of the chord is the diameter.

6. Equal arc pairs equal circumferential angles. Note that in a circle, there are an infinite number of circumferential angles of the same string.

Circumferential Angle Definition:

The circumferential angle was originally called the Janet angle because its vertex was on the circumference of the circle and the two sides intersected the circle, so it was renamed the Annette angle. In the same circle or equal circle, if the circumferential angles of the two circles are equal, then the strings (or arcs) to which they are paired are also equal; Conversely, the circumferential angles of the equal arcs are equal. The circumferential angles of the equal chord are equal or complementary, and the degree of the circumferential angle is equal to half of the degree of the arc to which it opposes.

For a circumferential angle, there must be an arc inside the corner, and the circumferential angle is usually said to be the circumferential angle on the arc, or the circumferential angle to which the arc is opposed. In addition, there is an arc on the outside of the angle, and we also say that the circumferential angle is the circumferential angle contained in this arc.

The circumferential law (also known as the law of conservation of angular momentum) is a law of physics that describes the laws of motion of rotating systems. The law stipulates that when an object rotates around a fixed axis, its angular momentum remains the same, unless there is an external moment.

More specifically, the circumferential law shows that the angular momentum l of a rotating system is conserved, i.e., the magnitude of l does not change until an external moment acts on the system. The external moment changes the angular momentum of the rotating system and thus changes its state of motion.

The circumferential law is a fundamental law in classical mechanics that applies to various situations of rotating motion systems, such as a rotating rigid body, a particle in circular motion, a charged particle in a magnetic field, etc.

Pi is a transcendent number and cannot satisfy the real number of any algebraic equation of integer coefficients, Pi =?, the base of the natural logarithm e=?It can be proved that there is an infinite number of transcendences. Pi is not a number of algebraic numbers, it is beyond the reach of algebraic methods.

Origin of Pi:

The first to get is the Greek Archimedes (about 240 B.C.), the first to give the last four decimal places of the accurate value is the Greek Ptolemy (about 150 B.C.), the first to calculate the last seven decimal places of the accurate value is our country's Zu Chongzhi, in 1610 the Dutch German mathematician Rudolph applied the inscribed and inscribed regular polygon to calculate the value, through the two-sided calculation to 35 decimal places, in 1630 Greenberg using Snell's improved method to calculate the value to 39 decimal places, which is the use of classical methods to calculate value of the most important attempt.

It's pi, right?

Generally, =

For more exactness, use x09 =

The heart must be determined, and the feet must be diligent, and it will be complete.

Circular law. Whatever is foreseen is established, and what is not foreseen is wasted. However, it is still not possible to predict, and you must have good execution and concentration.

This gave birth to another law, called the "law of the circle". The reason why the compass is successful in drawing a circle is because his body is moving. And the performance of unsuccessful is just the opposite, every day the heart is moving but the body is not moving, or the heart is also moving, so that it is only occasional or occasional luck that does things.

When drawing a circle, just the center of the circle does not move and the corners are walking, as long as you keep moving, whether you are buried to the left or to the right, the same circle will be drawn. If the left and right sides of the fillet are affected by external forces, that is, they cannot go to the left and cannot go to the right, and they have to be pulled out together. If you pull it inward together, the compass is not self-reliant and becomes a perseverance 1 word; If the left side pulls inward, the right side pulls outwards forcefully or pushes and pulls in the opposite direction, the fillet cannot move under the condition that the force is equal; If there is an external force on one side greater than the other, the compass will be inverted; If you want to make the compass go well and walk steadily, you must have a tall man touch the top head of the compass, no matter how the compass is drawn, no matter how the angle is adjusted, you will draw a satisfactory circle, the size of the circle is only adjusted and changed with the angle of the circle, grasp the hand power of the compass top with your heart, look at the whole plate and listen to the eight sides, everything is under control. Round all things and run, circle to avoid the edge and forward, unstoppable, the perfection of life and things is the heart of the annihilation of the same and always towards the goal of constant force running.

Generally taken.

or twenty-two out of seven.

, which is approximately equal to the wireless non-cyclic decimal.