Geometric Construction 1

An ellipse is the locus of a point which moves so that the sum of its distances from two fixed points (the loci) is a constant.  Construct the ellipse according to this definition by using the command "perpendicular bisector".

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Construct the ellipse as an envelope of its tangents.

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Given a point outside an ellipse, 4.gif (3218 bytes)

construct the pair of tangents:

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Construct the ellipse from the parametric representation

x = cos t

y = sin t

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Construct the tangents at a point of the ellispe as in the above construction.

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Construct the tangent from a point outside the ellipse as in the above construction.

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Construct an animation of a rectangle whose sides are tangent to a given ellipse/hyperbola.

Construct the ellipse from its tangent.