Khan Academy on a Stick
Introduction to Euclidean geometry
Roughly 2400 years ago, Euclid of Alexandria wrote Elements which served as the world's geometry textbook until recently. Studied by Abraham Lincoln in order to sharpen his mind and truly appreciate mathematical deduction, it is still the basis of what we consider a first year course in geometry. This tutorial gives a bit of this background and then lays the conceptual foundation of points, lines, circles and planes that we will use as we journey through the world of Euclid.
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Euclid as the father of geometry
We don't normally delve too far into history when talking about math, but sometimes it's important to have perspective about how some of our math concepts came about and how influential they have become.
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Basic geometry: language and labels
Before learning any new concept (mathematical or otherwise), it's important we learn and use a common language and label concepts consistently.
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Intro to lines, line segments, and rays
Let's get familiar with the difference between lines, line segments, and rays. Hint: a ray is somewhere between a line and a line segment!
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Drawing line segments example
Let's put our new knowledge of line segments to use in this example problem. We'll help you!
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Specifying planes in three dimensions
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Language and notation of the circle
Formal definition of a circle. Tangent and secant lines. Diameters and radii. major and minor arcs
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The golden ratio
An introduction to one of the most amazing ideas/numbers in mathematics
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Identifying rays
Identifying Rays
Introduction to Euclidean geometry
Roughly 2400 years ago, Euclid of Alexandria wrote Elements which served as the world's geometry textbook until recently. Studied by Abraham Lincoln in order to sharpen his mind and truly appreciate mathematical deduction, it is still the basis of what we consider a first year course in geometry. This tutorial gives a bit of this background and then lays the conceptual foundation of points, lines, circles and planes that we will use as we journey through the world of Euclid.