Overview:
The number pi (π) is one of the most important and useful numbers in math calculations involving circles, spheres, and other circular objects. It is an irrational number with a decimal that never repeats or ends. As a decimal, pi can be approximated by 3.1415926535.
What Is Pi?
As a number, pi is the ratio of the circumference of a circle to its diameter. If the perimeter of a circle could be unraveled and measured, it would equal the diameter times pi. Even though supercomputers have calculated the value of pi to over 10 trillion digits, it does not repeat those digits in a pattern.
How Is Pi Used in Calculating Circles?
Besides the circumference of a circle, pi can also be used to calculate the area of a circle in the formula A=πr2, where r is the radius (1/2 the diameter) of the circle. If a circle has a radius of 5 units, the area will be π∙52 or 3.1416 ∙25 square units , about 78.54 square units. A circle can also be divided into sections called sectors, like the pieces of a pie. The sector is measured by the length of the radius squared times pi times the fraction of the circle the sector covers. Circle graphs use sectors and fractions of the circle.
How Is Pi Used in Calculating Spheres?
A sphere is a circle in three dimensions, so that it is the set of points in space at a given distance from a central point. (Think of a ball or a soap bubble with a clear central point and radius.) The surface area S is measured by 4πr2. The volume V is measured in cubic units by 4/3πr3.
Other Fun Facts About Pi
Pi is more than an irrational number and mathematical workhorse. It has its own holiday, celebrated on March 14 (also known as 3/14), known as Pi Day. It is celebrated at many schools, including MIT. Some schools hold competitions to see how many digits of pi can be memorized and recited. As can be expected, round pies of all kinds are eaten.
Interested in geometry tutoring services? Learn more about how we are assisting thousands of students each academic year.
SchoolTutoring Academy’s is the premier educational services company for K-12 and college students. We offer tutoring programs for students in K-12, AP classes, and college. To learn more about how we help parents and students in Billings, MT visit: Tutoring in Billings, MT