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Geometric Logic Fundamentals

This worksheet covers fundamental concepts in geometric logic, including conditional statements, converses, inverses, contrapositives, and deductive reasoning.

Grade 9 Math GeometryGeometric Logic
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Includes

Multiple ChoiceFill in the BlanksTrue / FalseShort AnswerCustom

Standards

CCSS.MATH.CONTENT.HSG.CO.C.9CCSS.MATH.CONTENT.HSG.CO.C.10

Topics

geometrylogicconditional statementsdeductive reasoninggrade 9
7 sections · Free to use · Printable
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Geometric Logic Fundamentals

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Read each question carefully and provide your best answer. Show all your work for short answer questions.

1. Which of the following is the converse of the statement: "If a polygon is a square, then it has four sides"?

a

If a polygon has four sides, then it is a square.

b

If a polygon is not a square, then it does not have four sides.

c

If a polygon does not have four sides, then it is not a square.

d

A square has four sides.

2. What is the contrapositive of the statement: "If an angle is acute, then its measure is less than 90 degrees"?

a

If an angle's measure is less than 90 degrees, then it is acute.

b

If an angle is not acute, then its measure is not less than 90 degrees.

c

If an angle's measure is not less than 90 degrees, then it is not acute.

d

An acute angle measures less than 90 degrees.

3. A statement that can be written in the form "If p, then q" is called a   statement.

4. The   of a conditional statement switches the hypothesis and the conclusion.

5. The   of a conditional statement negates both the hypothesis and the conclusion.

6. The inverse of a true conditional statement is always true.

T

True

F

False

7. If a conditional statement is true, its contrapositive is also true.

T

True

F

False

8. Consider the following statements:

Premise 1: If an animal is a dog, then it is a mammal.

Premise 2: Fido is a dog.

What conclusion can be drawn using the Law of Detachment?

9. Consider the following statements:

Premise 1: If it is raining, then the ground is wet.

Premise 2: If the ground is wet, then the car will get dirty.

What conclusion can be drawn using the Law of Syllogism?

10. Given the diagram below, complete the two-column proof.

Given: Line AB intersects line CD at point E. ∠AEC and ∠BED are vertical angles.

Prove: ∠AEC ≅ ∠BED

ABCDE

Statement

Reason

1. Line AB intersects line CD at point E.

1. Given

2. ∠AEC and ∠CEB form a linear pair.

2.  

3. ∠CEB and ∠BED form a linear pair.

3.  

4. ∠AEC and ∠CEB are supplementary.

4. Definition of Linear Pair

5. ∠CEB and ∠BED are supplementary.

5. Definition of Linear Pair

6. m∠AEC + m∠CEB = 180°

6. Definition of Supplementary Angles

7. m∠CEB + m∠BED = 180°

7. Definition of Supplementary Angles

8. m∠AEC + m∠CEB = m∠CEB + m∠BED

8.  

9. m∠AEC = m∠BED

9. Subtraction Property of Equality

10. ∠AEC ≅ ∠BED

10.