The CIRCLE SONG
https://www.youtube.com/watch?v=ldnZevLaX6I
A circle is a shape
with all points on the circle the same distance
from the centre point.
A radius is a straight line from the centre
to the circle's edge.
A diameter is a line
across the endpoint of the circle, it passes through the centre point.
A circumference is
the distance round the circle.
Diameter d is twice the radius.
Radius r is half the diameter.
π is the circumference c, divided by the diameter.
π is 3.14 approximately, Circumference is π d or 2 π r,
Area is π r2.
Sylvain BOURDALÉ mathsb@free.fr http://mathSb.free.fr