Pi, generally expressed by π, is a common mathematical constant in mathematics and physics. It is defined as the ratio of the circumference to the diameter of a circle. It is also equal to the ratio of the area of a circle to the square of its radius. Accurate calculation of geometric shapes such as circle perimeter, circle area and sphere volume is the key value. In the analysis, π can be strictly defined as the smallest positive real number x satisfying sin(x) = 0, where sin is a sine function (defined by the analysis). The common decimal approximation of π is 3. 14 15926, and the approximate rate given by Zu Chongzhi is 22/7, and the secret rate is 355/13. Pi or π is one of the most important mathematical constants.

It is approximately equal to 3. 14 159. In Euclidean geometry, it represents the ratio of the circumference of any circle to its diameter.

This is the same as the ratio of the area of a circle to the square of its radius. Many mathematical formulas

science

And engineering involves π. This is an irrational number.

This means that it cannot be expressed by the fraction m/n.

Where m and n are integers. Therefore, its decimal representation will never end or repeat. Transcend irrationality

This is a century's figure

This means that there is no finite algebraic operation sequence on integer (power)

root

total

E) can be produced. Throughout the history of mathematics

In order to determine π more accurately and understand its properties, people have done a lot of work. The obsession with numbers even extends to the whole culture. Greek letter π

Pi is usually spelled in text.

This number comes from the Greek word for circumference. μετρο? "

May be William Jones in 1706.

A few years later, it was popularized by leonhard euler. This constant is sometimes called a cyclic constant.

Archimedes constant (not to be confused with Archimedes number)

Or Rudolph's number. π is the graph of English Department PI.2008-04-1319: 43:10 Supplement: π = φ.

Reference: hmm. * * */wiki/pi &； zh。 *** /w/index？ Title =% E5% 9c% 93% E5% 91%A8% E7% 8e% 87&; Variant =zh-

Wu = 14/7 or 3. 14 Wu is about 3. 14 16, which is the ratio of the diameter of a circle to its circumference. For example, the diameter of a circle is 1cm.

Then the circumference is centimeters. ...

Area of a circle

Circumference = 3.1428 571428 571428 571428 571428 57/kloc-0.

also

Pai (Wu) is a symbol in mathematics ~ used to calculate the area, perimeter and so on of a circle ~