Brief introduction of circumference:
The circumference of a circle refers to the length of a circle. The circle is inscribed with a regular N-polygon, the side length is set to an, and the circumference of the regular N-polygon is n×an. When n increases, the perimeter of a regular polygon is close to the perimeter of a circle.
Calculation method of circumference:
It refers to the mathematical phenomenon that a regular N-polygon is inscribed in a circle, its side length is set to an, and its perimeter is n×an. When n is increasing, the perimeter of a regular polygon is closer to the perimeter c of a circle, that is, n is close to infinity, and C=n×an. It is found in experience that there is a constant ratio between the circumference and diameter of a circle, and this constant is called pi (recorded in the west).
Circle profile:
A circle is a geometric figure. A figure composed of all points whose distance from a plane to a fixed point is equal to its fixed length is called a circle. When a line segment rotates around one endpoint on a plane, the trajectory of the other endpoint is called a circle.
Brief introduction and calculation method of pi;
1, Introduction to Pi
Pi refers to the ratio of circumference to diameter of a circle, that is, pi = circumference ÷ diameter, which is generally expressed by the Greek letter π and is a common mathematical constant in mathematics and physics. π is also equal to the ratio of the square of the area and radius of a circle, which is the key value to accurately calculate the geometric shapes such as the circumference of a circle, the area of a circle and the volume of a ball.
In the analysis, π can be strictly defined as the smallest positive number x satisfying sinx=0. Pi is written in the Greek letter π (pronounced [pa? ]), which is a constant (approximately equal to 3. 14 1592654), is the ratio of circumference to diameter. It is an irrational number, that is, an infinite cycle decimal.
2, the calculation method of pi
The circumference of a circle = pi × diameter, which is expressed by letters as c = π d. The circumference of a circle can also be expressed by the radius of a circle pi ×2× its radius, which is expressed by letters as c = 2 π r. A point set whose distance to a fixed point is equal to a fixed length is called a circle. This fixed point is called the center of the circle and is usually represented by the letter "O".
The line connecting the center of the circle with any point on the circumference is called radius, which is usually represented by the letter "R". Through the center of the circle, the line segment with two ends on the circumference is called diameter, which is usually represented by the letter "D".