Circles
A quick tutorial about circles to help you understand about calculating
the area and circumference.
Try the Online Circle Measurement
Tool.
If you know either the Diameter, Area or Circumference, the tool does the rest!
Circle |
Lines in Circles |
AB
= Diameter |
The circumference
of a circle is the actual length around the circle which is equal to 360°.
Pi (p)
is the number needed to compute the circumference of the circle.
p is
equal to 3.14.
Pi
is greek and has been around for over 2000 years!
In circles the
AREA is equal to 3.14 (p)
times the radius (r) to the power of 2.
Thus the formula looks like:
A= pr^{2}.
In circles the
circumference is 3.14 (p)
times the Diameter.
Thus the formula looks like:
2pr
or pd.
Related Links:
Measurement
of area and perimeter of other shapes.
Geometry
Tutorials