Miss Stanley
The Green School
Geometry Fall 2011
Name ________________________________
Date _________________________________
Lesson 2.2 Biconditionals and Definitions
Example 1: Writing a Biconditional
Conditional Statement:
If two angles have the same measure, then the angles are congruent.
Converse Statement:
Biconditional Statement:
Example 2: Writing Good Definitions.
A good definition…
Is this a good definition?
1.
a. An airplane is a vehicle that flies.
2.
3.
Example 3: Writing a Condition as a Biconditional
How can you tell if you can write a biconditional definition?
Conditional:
If two lines are perpendicular, then they intersect to form right angles.
Converse:
Biconditional Definition:
** Are the conditional and the
converse true?
** Can you write a
biconditional definition?
Each conditional statement below is true.
1. Write its converse.
2. If the converse is true, combine the statements as a biconditional.
If x = 12, then 2x – 5 = 19.
If x = -10, then x2 = 100.
1.
1.
2.
2.
Test each statement below to see if it is reversible.
If so, write it as a true biconditional.
If not, write not reversible.
Parallel planes are planes that do not intersect.
A triangle has sharp corners.
Is each statement below a good definition? If not, explain.
A cat is an animal with whiskers.
A square is a figure with two pairs of parallel sides.
A segment is a part of a line.
Parallel lines do not intersect.
Review Questions:
1. Write the converse and the Biconditional of the Conditional Statement.
Conditional:
Converse:
If a whole number ends in zero,
then that whole number is even.
Is the coverse true?
Biconditional: