Download Definitions Goals: · Practicing writing definitions. · Define special

August 21, 2012
Definitions
Goals:
· Practicing writing definitions.
· Define special angle relationships.
So....'Which ones are the Widgets?'
Why....?
How did you determine your answer...?
August 21, 2012
Writing definitions....
As you write definitions, to determine whether or not your
definition works, you want to look for a counterexample.
But what is a counterexample?
A square is figure with four equal sides.
Is this a good definition? Take a minute to determine why or why
not it is a good definition, provide a counterexample if needed.
A better and more precise definition would be.....
A square is a 4-sided figure that has all sides congruent and all
angles measuring 90 degrees.
August 21, 2012
When writing definitions keep the following in mind....
- Classify your term. What is it?
- Differentiate your term. How does it differ from others in that
class?
- Test your definition by looking for a counterexample.
We will try a few together first...
Parallel lines -
coplanar lines that never intersect.
August 21, 2012
Skew lines -
noncoplanar lines that do not intersect.
Perpendicular Lines -
lines that meet at 90o angles.
August 21, 2012
Turn your books to page 50 and write your own
definitions with a partner.
Vertical Angles -
non-adjacent angles formed by two
intersecting lines.
Linear Pair of Angles two adjacent angles whose sum is 180o.
August 21, 2012
Complementary Angles -
two angles that have a sum of 90o.
Supplementary Angles -
two angles that have a sum of
180o.
August 21, 2012
Calculators!
August 21, 2012