Constructing the Twin Circles
Now that we know how to get
their radius
, we are able to construct the Twin Circles of Archimedes in an
arbelos
.
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)
Drag the
red point N
to change the shape of the arbelos. Use the navigation buttons to go through the construction steps:
Arbelos with a perpendicular line at its notch N.
Radius
r
of the twin circles
by using the small semicircles' radii
a
and
b
.
Two parallel lines with distance
r
from the notch N. The center points of the twin circles will be on these lines.
The circle around
C
with radius
a+r
gives us the first twin circle's center point E.
First twin circle.
The circle around
D
with radius
b+r
gives us the second twin circle's center point G.
Second twin circle.
Your Tasks
Construct the Archimedean twin circles with ruler and compass on paper.
Try to create a dynamic construction of the twin circles with an interactive geometry software (e.g.
GeoGebra
).
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Constructing the Radius
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Contents
Next:
Pappus Chain