Hi Peilin,
The number π (pi) is a mathematical constant that is the ratio of a circle’s circumference to its diameter, approximately equal to 3.14159. The number π appears in many formulas across mathematics and physics. It is an irrational number, meaning that it cannot be expressed exactly as a ratio of two integers, although fractions such as 22/7 are commonly used to approximate it.
Pi is most commonly used in certain computations regarding circles. Pi not only relates to circumference and diameter.
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