Value of pi

Pi is an irrational number -- a number with an unending string of non-repeating digits after the decimal point. While it has been calculated to more than 10 trillion places, most of the time just a few decimal places will do. We'll look at two different ways to calculate pi: By measuring a circle and by solving a mathematical equation. Stephanie Ellen teaches mathematics and statistics at the university and college level. She coauthored a statistics textbook published by Houghton-Mifflin. She has been writing professionally since 2008. Ellen holds a Bachelor of Science in health science from State University New York, a master's degree in math education from Jacksonville University and a Master of Arts in creative writing from National University. Photo Credits

The number represented by pi (π) is used in calculations whenever something round (or nearly so) is involved, such as for circles, spheres, cylinders, cones and ellipses. Its value is necessary to compute many important quantities about these shapes, such as understanding the relationship between a circle’s radius and its circumference and area (circumference=2πr; area=πr 2). Pi also appears in the calculations to determine the area of an ellipse and in finding the radius, surface area and volume of a sphere. Our world contains many round and near-round objects; finding the exact value of pi helps us build, manufacture and work with them more accurately. Historically, people had only very coarse estimations of pi (such as 3, or 3.12, or 3.16), and while they knew these were estimates, they had no idea how far off they might be. The search for the accurate value of pi led not only to more accuracy, but also to the development of new concepts and techniques, such as limits and iterative algorithms, which then became fundamental to new areas of mathematics. Finding the actual value of pi Between 3,000 and 4,000 years ago, people used trial-and-error approximations of pi, without doing any math or considering potential errors. The earliest written approximations of pi are The first rigorous approach to finding the true value of pi was based on geometrical approximations. Around 250 B.C., the Greek mathematician Archimedes drew polygons both around the outside and within the in...

Whether you want to very accurately calculate the area of a circle, paint the digits of Pi on your room, face, a t-shirt, or your baby brother, or memorize digits of Pi to impress your friends... Note: Memorizing Pi is not guaranteed to impress your friends. But it can be fun as a challenge. :) • The first 10 and 50 digits of Pi: 3.14159265 35897932384626433832795028841971693993751 • More digits: Scroll down to see the first 10,000 digits of Pi at the bottom of this page, or grab even more using the links below. • Files containing digits: • The Pi searcher can show digits of Pi anywhere in the first 200 million digits, using the second line in the search box. Curious what digits are from position 50,000,000 to 50,000,050? Find out... Search For: See Sources of lots of Pi Need more than a million digits? Here are some places to look: • 4 million digits (compressed): • 50 million digits (compressed, special): You can download 50 million from the Pi searcher • 4 billion digits: Available in various formats from • 5 trillion digits (requires special viewer): Alexander Yee makes Alternately, you could download a program to compute pi and compute them yourself. Alexander Yee's 10,000 digits of Pi formatted for humans 3. 1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 8214808651 3282306647 0938446095 5058223172 5359408128 4811174502 8410270193 8521105559 6446229489 5493038196 4428810975 6659334461 2847564823 3786783165...

Pi (π) has been known for almost 4000 years—but even if we calculated the number of seconds in those 4000 years and calculated π to that number of places, we would still only be approximating its actual value. Here’s a brief history of finding π. The ancient Babylonians calculated the area of a circle by taking 3 times the square of its radius, which gave a value of pi = 3. One Babylonian tablet (ca. 1900–1680 BC) indicates a value of 3.125 for π, which is a closer approximation. The Rhind Papyrus (ca.1650 BC) gives us insight into the mathematics of ancient Egypt. The Egyptians calculated the area of a circle by a formula that gave the approximate value of 3.1605 for π. The first calculation of π was done by Archimedes of Syracuse (287–212 BC), one of the greatest mathematicians of the ancient world. Archimedes approximated the area of a circle by using the Pythagorean Theorem to find the areas of two regular polygons: the polygon inscribed within the circle and the polygon within which the circle was circumscribed. Since the actual area of the circle lies between the areas of the inscribed and circumscribed polygons, the areas of the polygons gave upper and lower bounds for the area of the circle. Archimedes knew that he had not found the value of π but only an approximation within those limits. In this way, Archimedes showed that π is between 3 1/7 and 3 10/71. A similar approach was used by Zu Chongzhi (429–501), a brilliant Chinese mathematician and astronomer. Zu Cho...

Value of Pi The value of pi is the ratio of the circumference of a circle to its diameter. The pi symbol is denoted as π. It is also called Archimedes' constant which was named after the Greek mathematician, Archimedes, who created an algorithm to approximate the pi value. The value of pi is irrational, which means that the count of digits after the decimal point is infinite. It is used as either 3.1415929 or 22/7. In geometry, it is used in calculating the surface area, volume, and circumference of various three-dimensional shapes. 1. 2. 3. 4. 5. 6. 7. 8. What is the Value of Pi? The value of 'pi' is constant, which means it cannot be changed. It is an If we divide the circumference by the diameter, we get approximately 3.14. It should be noted that no matter what size of a circle we draw, the ratio of the circumference to its diameter will always be the same. Formula for Pi The value of pi can be obtained by dividing the circumference of a circle by its diameter. Since pi is the ratio of the circumference of a circle to its diameter, the formula for calculating π is: π = Circumference/Diameter One interesting statement that helps us to remember the value of pi is "How I wish I could calculate pi". By counting the number of letters in each word, we can easily write the value of pi. Since 'How' has 3 letters; 'I' - 1 letter, 'wish' - 4 letters, 'I' - 1 letter, 'could' - 5 letters, 'calculate' - 9 letters, 'pi' - 2 letters. Therefore, the value of pi approximated to 6 How t...