Tuesday, March 25, 2014

A world full of Circles

Circumference

  • What is a circle?
  • A circle is a round plane figure whose boundary (the circumference). 

 

 












        Now lets talk about circumference !!!!!!
  •    Circumference is the linear distance around the edge of a closed curve or circular object. 
             Relationship with Pi
  • The circumference of a circle relates to one of the most important mathematical term in all of mathematics terms . This term, pi, is represented by the Greek letter π. The numerical value of π is 3.14159 26535 89793 ...
  • The first term is the ratio of a circle's circumference to its diameter and equals π. While the second term is the ratio of the diameter and two times the radius and is used as to convert the diameter to radius in the same ratio as the first, π. Both proportionality constants combine in respect with circumference c, diameter d, and radius r to become:
Formula: C = 3.14(d)=2(3.14)(r)

        Example
Find the circumference and diameter of each circle
  • The radius of a circle is 2 inches. What is the diameter?
               Solution: d=2(r)
               d= 2(2inches)
               d= 4 inches
  • The diameter of a circle is 3 centimeters. What is the circumference?
              Solution: C= (3.14)(d)
                              C= (3.14)(3cm)
                              C= 9.42cm


Thank you !!!!!!!!!