Pi is the ratio of the circumference ( the perimeter) of a circle to its diameter.
You might have learned in school that if C is the circumference of the circle., then C=2Pir or C=pixd
from which we say pi = C/d or the ratio of the circumference of the circle to its diameter.
This has been known since ancient times! William Jones gave us the symbol we currently use for it. This comes from the 16th letter in the Greek alphabet.
So we use it to measure circles because of what it is.
Pi times the diameter of a circle gives its circumference.
Pi is related to circles as it is used to measure the area, circumference, surface area and volumes of any 2-D or 3-D shape that has circles or circle-related surfaces. In the case of area of a circle, it is measured as pi x r x r, OR pi x r2 where r is the radius of the circle. The relation between the radius and the circumference is also shown by by pi; circumference / diameter ( or 2 x radius) = Pi OR circumference = pi x diameter = 2 x pi x r All related shapes like cones, cylinders, spheres, toruses, and even doughnuts can be measured using Pi. Pi is usually given as 22/7, which doesn't even come that close. Another common value is 3.14, which is the cut off form of its value.
Pi is used in basketball to measure the curcumference of diameter in the basketball itself, the hoop, the rim, and the ring that the players do the jump ball in.-Sanderson Pickweal .
The circumference of a circle is 2 pi r, where r is the radius, or it is pi d, where d is the diameter.there is no circuference of pi. Circumference refers to the outer edges of circles
C=2(pi)r
Archimedes of Syracuse
Pi has undoubtedly contributed to math. Pi can be used for calculating circles and was used to measure distances without doing it the harder way....
Pi (3.141...) is used for circles, and circles only. You use it to find the area and circumfrence.
Angular measure of a circle: 2*pi radians. Circumference of a circle with diameter d units: d*pi units
Circumference of any circle = 2*pi*radius or pi*diameter
Pi times the diameter of a circle gives its circumference.
Because of the radius of the circle
Pi is the ratio of a (perfect) circle's circumference to its diameter. It was, and still is, used to make more accurate measurements of things containing circles or parts of circles. Pi also shows up in trigonometry and higher maths.
Pi is used anytime there is a circular (as opposed to linear) geometry involved. Examples include circles, cylinders, spheres, and other cruves.
Because all circles are similar.
The Greek word for perimeter begins with the letter pi, and since circumference and perimeter are the same the letter Pi was used.
In circles in nature.