A circle's circumference or perimeter is the distance around the circle.
This is shown in red in the figure below. Starting at point A, going all
around the circle, and ending on the same point A represents the circumference
of the circle.
In this method, we have to select the diameter of the circle and there is a dot on the circle. When we rotate the circle, the dot will also rotate on along the circle. We will rotate the circle until dot is reached up to start point and at this point length of the horizontal line is equal to perimeter of the circle. Thus, we can calculate the value of
.
Through above method, we can calculate at most ten values of
for different diameters of the circle and thus we get the better approximation of the
by calculating the average value
of .
HOW TO USE THIS APPLET :
Concept of calculating the value of
based on formula that circumference=2 r, where r is
the radius of the circle or in other way, we can say that circumference = diameter* .
It means if we know diameter and perimeter, then we can find the value of .
Here, in this Applet, when we select the diameter, then the circle of the selected diameter
will be drawn. Then, click on start button and scroll the horizontal scroll bar, until red dot
is reached again on the horizontal and some value appear in diameter and circumference text
box. At this time vertical scroll bar and start button is inactive. Now, click on the next
button to see the value of . In this way we can see the ten different values of
, during ten iteration and its average value will be calculated each time.
In the mean time, if we want to start again then we can click on the "REFRESH" button.
