Section 2 2 cont Definitions Definition Activity Work
- Slides: 7
Section 2 -2 (cont. ) Definitions
Definition Activity • Work with your surrounding classmates and write the definition for a “Polyglob. ”
Good Definitions • A good definition uses clearly understood terms. The terms should be commonly understood or already defined. • A good definition is precise. Good definitions avoid words such as large, sort of, and almost. • A good definition is reversible. That means that you can write a good definition as a true biconditional.
Example (Me) Show that this definition of perpendicular lines is reversible. Then write it as a true biconditional. Definition: Perpendicular lines are two line that intersect to form right angles. Conditional: If two lines are perpendicular, then they intersect to form right angles. Converse: If two lines intersect to form right angles, then they are perpendicular. Biconditional: Two lines are perpendicular if and only if they intersect to form right angles.
Example (We) Definition: An airplane is a vehicle that flies. Conditional: If it is an airplane, it is a vehicle that flies. True Converse: If it is a vehicle that flies, then it is an airplane. False – counterexample: helicopter
Example (You) Definition: A right angle is an angle whose measure is 90. Conditional: Converse: Biconditional:
Homework: Section 2 -2 p. 90 #’s 18 -23, 33 -37
