ELLIPSE

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ELLIPSE
By Insuk Dunne
Gulf Coast Community College
April 2001
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ELLIPSE
These are questions we will try to answer in the
following pages
What is it ? Where does it fit in our everyday
lives ? Where can we find it in our environment
? Is a circle an ellipse ? How would you draw an
ellipse ?
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ELLIPSE
What is it ?
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Ellipse as defined by Websters Collegiate
dictionary is a closed plane curve generated by
a point moving in such a way that the sums of its
distances from two fixed points is constant.
Or a more specific definition that can be
found Ellipse commonly defined as the locus of
points P such that the sum of the distances from
P to two fixed points F1, F2 (called foci)
are constant. That is, distanceP,F1
distanceP,F2 2 a, where a is a positive
constant.
If you are interested in finding out more about
the family, history, formulas, or properties on
the ellipse you can use the button on the
hyperlink page. To go there click this button
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ELLIPSE
Where does it fit in to our everyday lives ?
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Did you know that you look at elliptical shapes
every day ?
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Elliptical shapes are all around us
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ELLIPSE
Where can we find it within our environment ?
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From earliest times, astronomers assumed that
the orbits in which the planets moved were
circular yet the numerous catalogs of
measurements compiled especially during the 16th
century did not fit this theory. At the
beginning of the 17th century, Johannes Kepler
stated three laws of planetary motion that
explained the observed data the first law being
that the orbit of each planet is an ellipse with
the sun at one focus.
click here to go to the hyperlink page and more
information
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An atom is made up of protons and neutrons in
a nucleus and electrons flying around the nucleus
in elliptical orbits
For more information on atomic structure go to
hyperlink page by clicking this button
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There are other places within our natural
environment that we can find the ellipse, Or an
elliptical shape. Did you know that it is
even within the human anatomy?
Yes, the human eye is shaped like an ellipse.
For some pictures showing eyes in motion and some
other impertinent information click this button
and go to the hyperlink
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Some other places within nature are

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ELLIPSE
Is a circle an ellipse ?
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There are many arguments in the mathematical
and scientific world around the ellipse, one of
the most prevalent being whether a circle is an
ellipse. However, if you place the two foci of
an ellipse together and draw your ellipse you end
up with a circle!
Foci 1
Foci 2
Foci 1
Foci 2
For more information on atomic structure go to
hyperlink page by clicking this button
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ELLIPSE
How would you draw an ellipse ?
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Did you know you could draw an ellipse with a few
simple items in your home ? All you have to do
is place a piece of paper on the board, and stick
in the two pins (not too close together). Loop
the the thread around the pins and pull taut
with the tip of the pen. Now move the pen around,
always keeping the loop of thread taut. As the
pen rotates around the two pins it will trace
out an ellipse!
For more information on how to draw an ellipse
click on this button
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ELLIPSE
As you have seen an ellipse is a shape found
in our every day lives, in our environment, and
even within our own anatomy. You have learned
about the argument about the circle and the
ellipse, also how to draw an ellipse. I hope you
have enjoyed and learned more about the
ellipse.
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Table of References
1. Websters ninth new collegiate dictionary 2.
http//www.xahlee.org/SpecialPlaneCurves_dir/elli
pse.html 3. http//www.encyclopedia.com/ 4.
http//www.chem4kids.com/atoms/structure.html
5. http//chickscope.beckman.uiuc.edu/explore/e
ggmath/shape /pins.html 6. http//ootips.org/elli
pse-circle.html
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For more information click on the appropriate
button
Family, history, formulas, or properties
type ellipse as your search word, then click
on planetary orbits
Planetary Orbits
Atomic structure
Eye in motion
Arguments circle/ellipse
How to draw an ellipse
To return the the last slide shown click here