Transcript What

Axiomatic systems
By Micah McKee
VOCAB:
Axiomatic system
Postulate/Axiom
Theorem
Axiomatic system
Line segment
Ray
Point
Line
Plane
An Axiomatic system
• “In mathematics, an axiomatic system is any set of axioms from which
some or all axioms can be used in conjunction to logically derive
theorems. A mathematical theory consists of an axiomatic system and
all its derived theorems.”
An Axiom/postulate
• Is true, but can’t be proven
A theorem
• Is true but must be proven
A line segment is LIKE a single string of
spaghetti pasta.
A line segment is:
Part of a line connecting two points.
It has definite end points.
The word "segment" is important, because a line normally extends in both directions without end.
A ray is LIKE a space gun.
• A ray is also LIKE a laser beam
The point A is considered to be on a member of the ray; Part of a line connecting two points.
Some terms are undefinable. Because of this
we use KINDA LIKES to help define them.
• Point
• Line
• Plane
Point
• A point is KINDA LIKE a poppy seed on a bagel
A point: An exact location. It has no size, only position.
A line is LIKE a line to get into a one direction
concert.
A geometric line is:
A geometrical object that is straight, infinitely long, and infinitely thin.
and extends forever in both ways .
Plane
A plane is KINDA LIKE a huge pizza crust
A plane is the two-dimensional analogue of a point (zero dimensions),
a line (one dimension) and three-dimensional space
Euclid's Postulates:
• 1. A straight line segment can be drawn joining any two points.
• 2. Any straight line segment can be extended indefinitely in a straight
line.
• 3. Given any straight line segment, a circle can be drawn having the
segment as radius and one endpoint as center.
• 4. All right angles are congruent.
• 5. If two lines are drawn which intersect a third in such a way that the
sum of the inner angles on one side is less than two right angles, then
the two lines inevitably must intersect each other on that side if
extended far enough. This postulate is equivalent to what is known as
the parallel postulate.
Helpful ways to determine if it Is a axiom or if
it is a theorem.
• If it is an axiom then it is true but cant be proven.
• If it is a theorem it is true but must be proven.
• You can read more about it at this source;
• http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm
Examples
• Q: What is the difference between a
line and a line segment?
• Answer: A line is straight (no curves),
has no thickness, and extends in both
directions without end (infinitely).
• A line segment is a part of a line that
is bounded by two distinct end points,
and contains every point on the line
between its end points.
• So a line extends in both directions
forever a line segment is bound by
two distinct points.
• Q: what are the undefined terms
and why are they undefinable?
• Answer: The terms in this unit are
line segment, ray, point, line, and
plane.
• Line segment: Part of a line
connecting two points.
• Ray: Part of a line connecting two
points.
• Point line and plain are left and
they are undefinable. They are
undefinable because they can not
be put into a category or box.
Practice problems
• 1. What is the difference between a line and a ray?
• 2. What makes a term undefinable?
• 3. See fig 1, which example is a ray? Explain your answer.
• 4. list the three undefined terms?
• 5. See fig 1, which example is a line segment?
Fig 1.
Practice problems key.
• 1. A line extends in both ways forever, a ray has a starting point and
only extends in one way forever
• 2. The fact the these terms don’t truly exist
• 3. (iv) is the ray because it extends forever in one direction and
contains two points.
• 4. point, line. Plane.
• 5. (iii) is the line segment because it is a part of a line containing two
points.
Source citation
• "5 Axioms of Geometry - Google Search." 5 Axioms of Geometry Google Search. N.p., n.d. Web. 03 Dec. 2014.
• "Line." Definition of. N.p., n.d. Web. 08 Dec. 2014.
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