Khan Academy on a Stick : Points, lines, and planes

Khan Academy on a Stick

Geometry

Points, lines, and planes
Angles and intersecting lines
Congruent triangles
Perimeter, area and volume
Similarity
Right triangles
Special properties and parts of triangles
Quadrilaterals
Circles
Logical reasoning
Transformations
Worked Examples

Euclid as the Father of Geometry
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Euclid and his Elements (and how much Abraham Lincoln liked them)
Language and Notation of Basic Geometry
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Understanding basic ideas in geometry and how we represent them with symbols
Lines, Line Segments, and Rays
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Difference between lines, line segments, and rays
Specifying planes in three dimensions
Language and Notation of the Circle
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Formal definition of a circle. Tangent and secant lines. Diameters and radii. major and minor arcs
The Golden Ratio
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An introduction to one of the most amazing ideas/numbers in mathematics
Identifying Rays
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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.

Algebraically determining segment length

In this tutorial, you'll flex both your algebra and geometry muscles at the same time. You'll do this by applying the right amount of spray tan (which is needed for properly flexing any muscle) and then solve problems about line segments using algebra!