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Grade 8:  The Learning Equation Math

33.02 Topology

3icon.gif (4368 bytes)

Transformations

Refresher pp 74-75

Learning Outcomes:

The student will:

topology - "regions  study".   Topology is the mathematical study of properties of objects which are preserved through deformations, twistings, and stretchings. (Tearing, however, is not allowed.) A Circle is topologically equivalent to an Ellipse (into which it can be deformed by stretching).

ellipse.gif (17689 bytes)

Ellipse:

Source:  Ellipse--from Eric Weisstein's World of Mathematics

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source:  Mathmania Tour

Topology, precisely, is the branch of mathematics that deals with the properties of geometric configurations that are unaltered by elastic deformations.   It is easy to see why Space Rollercoasters were fun. One of the best things about them was that the tubes were flexible. Since the tubes were flexible, they could change shape as you slid through them! Going on the same Space Rollercoaster twice was like going on two different ones. You never really knew which direction you would be turning next because the tube was moving, curving and stretching as you passed through it.

 

arc.gif (891 bytes)

arc - part of a curve
region.gif (1287 bytes) region - areas completely or partly enclosed by arcs
vertex.gif (1027 bytes) vertex - point of intersection of the sides of a polygon or arcs of a region
region.gif (1287 bytes) vertices - plural of vertex.  There are 5 vertices joined by arcs in this example.
oddvertex.gif (1072 bytes) degree of a vertex - the number of arcs that meet at a vertex.  The degree of this vertex is 3.
oddvertex.gif (1072 bytes) odd vertex - when an odd number of arcs meet at a vertex
evenvertex.gif (1022 bytes) even vertex - when an even number of arcs meet at a vertex
network.gif (1395 bytes) network - consist of vertices that are all joined by arcs
traversble.gif (1190 bytes) traversable - a network that  can be traced in one continuous path by moving along every arc exactly once.  Traversable networks can have no more than two odd vertices.

 

Math Forum: Leonard Euler and the Bridges of Konigsberg

Beyond Numbers - coloring maps

Ideas, Concepts, and Definitions - 4 color  maps

Mathematical Surfaces

Fancy Knots and Links

Tangle Calculator

Java Applet: Curvature Flow

The Seven Bridges of Konigsberg

Is it possible to take a bike ride in which you crossed each of the 7 bridges exactly once.?

7bridges_small.jpeg (25826 bytes)

source:  MTH1110/MAT1830 Home Page at: http://www.maths.monash.edu.au/~johncs/mat1130/

Math Forum: The Bridges of Konigsberg, Page 2

 

Key Terms:

network, vertex, arc, region, degree of a vertex, odd vertex, traversable

Prerequisite Skills:

mobiuspage.gif (13060 bytes)

Mobius Band

The standard Mobius band is formed by joining the ends of a rectangle with one twist of 180 degrees.

mobiuspage3.gif (13851 bytes)

This Mobius band has three twists and is not homotopic to the standard embedding. As long as we join the ends of a rectangle with an odd number of half-twists, the resulting surface is non-orientable.

source:  The Möbius Band

Interactive Mobius band:   Möbius Strip -- from Eric Weisstein's World of Mathematics

 

 

 

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