The number π (/ paɪ / ⓘ; spelled out as pi) is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle 's circumference to its diameter. It appears in many formulae across mathematics and physics, and some of these formulae are commonly used for defining π, to avoid relying on the definition of the length of a curve.

Draw a circle with a diameter (all the way across the circle) of 1. Then the circumference (all the way around the circle) is 3.14159265... a number known as Pi. Pi (pronounced like "pie") is often written using the greek symbol π. The definition of π is: of a Circle.

For most practical uses, you can assume it is 3.142. Some people have written computer programs and calculated it to an astonishing accuracy. For example some have calculated pi to 200 million digits.

2020年1月27日 · The number equivalent to pi, 3.142 to three decimal places, is the number that you get when the circumference is any circle is divided by its diameter. This will be the case regardless of the size of the circle you are using.

1999年5月17日 · Succinctly, pi—which is written as the Greek letter for p, or π—is the ratio of the circumference of any circle to the diameter of that circle. Regardless of the circle's size, this …

2022年4月28日 · How the value of pi 3.142? Because pi is 3.141592654 .... to infinity and rounded to 3 decimal places is 3.142. Copyright ©2025 Infospace Holdings LLC, A System1 …

2022年12月23日 · 3.142 are only the first three digits of Pi. It is an irrational number and goes on infinitely. It is one of the fundamentals of the universe in which we live. There does not seem to be a 'why'...