Bankoff circle

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In geometry, the Bankoff circle, which is equal in area to each of Archimedes' twin circles, was created by Leon Bankoff.^[1]

Contents 1 Construction 2 Radius of the circle 3 References 4 External links

[edit] Construction

The Bankoff circle created by with three semicircles that create an arbelos. A circle is then formed with three of its points P_i tangent to each semicircle. Another circle is then created with three of its points being the cusp formed by the two inner semicircles and the two intersecting points between the first circle and the two inner semicircles.

[edit] Radius of the circle

If r = AB/AC, then the radius of the Bankoff circle is:

[edit] References

• Eric W. Weisstein, Bankoff Circle at MathWorld.

[edit] External links

• Bankoff Circle by Jay Warendorff, The Wolfram Demonstrations Project.