The Geometry of a Circle

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Everything You Need To Know About the Geometry of a Circle

Geometry of a circle
D. Russell

The circumference of a circle is the measured total  length around a circle, which when measured in degrees is  equal to 360°. Pi (p) is the fixed ratio used  to calculate the circumference of the circle. 

p is equal to 3.14.

Pi is greek and was discovered around 200 BC, although it appears the Babylonians knew of the concept .

For the measurement of the area of a circle, the relationship of the radius squared multiplied by  3.14 (p)  will arrive at the correct answer.  
As a  formula, this  looks like:
A= pr2.

The relationship of the diameter to the circumference of a circle is defined as : circumference is 3.14 (p) times the diameter. 
So  the formula is written as::
pd.  So this can also be written as 2rd (diameter = 2 time radius)

Younger students can easily cut string the length of the circle in order to measure the distance around the circle.

 In math, the concept of circles will come up again and again from kindergarten on through to college math.  A circle is a two dimensional shape made by drawing a curve that is the same distance all around from the center. Circles have many components including: chords, curves, diameter, radius, tangents, arcs, sectors, semi circles and central angle to name a few. It was Archimedes who developed the formula for determining the area of a circle.