The approximate value is equal to 3. 14 1592654, which is positive if it is greater than 0. Positive number is a mathematical term. Numbers greater than 0 are called positive numbers, and 0 itself is not a positive number. Positive numbers and negative numbers represent quantities with opposite meanings. On the number axis, all positive numbers are on the right side of 0.

π is a constant (approximately equal to 3. 14 1592654) and is the ratio of circumference to diameter. It is an irrational number, that is, an infinite cycle decimal. In daily life, pi is usually expressed as 3. 14, which is used for approximate calculation.

Uyghur is the lowercase form of the16th Greek letter:

The symbol Wu is also the first letter of the Greek π ε ρ ρ ρ α (meaning periphery, region, circumference, etc.). ). 1706, the British mathematician William Jones (1675-1749) used "π" to express pi for the first time. 1736, Euler, a great Swiss mathematician, also began to express pi with Wu. Since then, Wu has become synonymous with pi.