Find the "symbol" in the lower right corner of the mobile phone input method, select "Greece" under the "symbol" option, and then enter and select "π".
In the input method, if you enter "Pai" with the full spelling input method, the "π" option will automatically jump out and you can choose to enter.
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, that is, π = the area of a circle ÷ radius 2 is the key value to accurately calculate the geometric shapes such as the circumference of a circle, the area of a circle, the volume of a sphere, etc.