Prentice Hall Geometry

The negation of a statement p is the opposite of the statement. The symbol is tilde p  and is read “not p.” The negation of the statement “The sky is blue” is “The sky is not blue.” You can use negations to write statements related to a conditional. Every conditional has three related conditional statements.

Below are the truth values of the related statements above. Equivalent statements have the same truth value.

Statement Example Truth Value
Conditional If m angle , eh equals , 15 comma  then angle eh  is acute. True
Converse If angle eh  is acute, then m angle , eh equals , 15 . False
Inverse If m angle eh not equal to 15 comma  then angle eh  is not acute. False
Contrapositive If angle eh  is not acute, then m angle eh not equal to 15 . True

A conditional and its contrapositive are equivalent statements. They are either both true or both false. The converse and inverse of a statement are also equivalent statements.


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Table of Contents

Prentice Hall Geometry Chapter 1 Tools of Geometry Chapter 2 Reasoning and Proof Chapter 3 Parallel and Perpendicular Lines Chapter 4 Congruent Triangles Chapter 5 Relationships Within Triangles Chapter 6 Polygons and Quadrilaterals Chapter 7 Similarity Chapter 8 Right Triangles and Trigonometry Chapter 9 Transformations Chapter 10 Area Chapter 11 Surface Area and Volume Chapter 12 Circles Skills Handbook Reference Visual Glossary Selected Answers Index Acknowledgments