1. Enter the pinyin of "Pai" and select "π" to type "π".

2. "π" In the setting of the input method, you can enter the "π" character by finding the Greek phonetic symbol.

Pi in the Greek alphabet? π (pronounced pài) is a constant (approximately equal to 3. 14 1592654), which 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. The fractional part 3. 14 1592654 is enough for general calculation. Even if engineers or physicists want to make more accurate calculations, they only need to take the values to a few hundred decimal places at best.

Reference link: Baidu Encyclopedia -Pi