2.3 Homework Answers
10.) Inductive Reasoning12.) Valid
16.) Invalid 18.) Invalid
20.) A; Complementary angles are not necessarily adjacent so
they may not form a right angle.
26.) Either Andre is less than 35 years old, or he is not a
natural-born citizen. Among the possible answers: Since there
are 3 criteria to be eligible and he meets 1, he must not meet 1
of the remaining 2.
2.4 Homework Answers
12.) Conditional: If a lunar eclipse occurs, then Earth is
between the Sun and the Moon. Converse: If Earth is
between the Sun and the Moon, then a lunar eclipse occurs.
16.) False; possible answer: Felipe could be a swimmer
22.)no; possible answer: y = -8
2.5 Homework Answers
8.) Statements Reasons
1. C = 9f + 90 Given
2. 102 = 9f + 90 Substitution
3. 12= 9f Subtraction Property of Equality
4. f = 4/3 Division Property of Equality.
10.) Definition of congruent segments; Substitution;
Subtraction Property of Equality; Subtraction Property of
Equality; Division Property of Equality
12.) Reflexive Property of Congruence
14.) Symmetric Property of Equality
50.) Inductive Reasoning
Have you ever wanted something so bad that you had to fight
for it? (NOT literally!) Maybe it was an allowance raise, a
car, your own room, or a later curfew? What types of
justifications did you use or say? Write down what you were
arguing/debating for and how you tried to PROVE you were
2.6 Proof Strategy:
Start with the hypothesis of the conditional, given Hypothesis or
information, or information in the diagram.
*Draw a picture or mark information
on a diagram already given.
Apply deductive reasoning. *Definitions *Properties
Prove that the conclusion of the conditional is true.
*Always be thinking about how you can get the conclusion to happen...
what makes the conclusion true?
Given: L1 and L2 form a linear pair
Prove: L1 and L2 are supplementary
Given: L1 and L2 are supplementary
L2 and L3 are supplementary
Prove: L1 ≅ L3
Given: LA and LB are right angles
Prove: LA ≅ LB
Given: L1 and L2 are complementary
L2 and L3 are complementary
Prove: L1 ≅ L3
Reference Sheet for Proofs:
Get out a clean sheet of paper. Label one side Definitions and the
other side Theorems.
Proof Writing 101:
1. Start with 2 columns, labeled Statements & Reasons
2. Number your statements and reasons so that they match
*Reason #1 has information about Statement #1
*Reason #3 explains how to move from statement #2 to #3
3. Do NOT make your proofs look like the book's proofs
*Properties identified by name
*Definitions written as "If..., then..." sentences
*Theorems written as "If..., then..." sentences
4. Abbreviate when you can
Partner Practice... Work with your partner on the following (this is your
Pg. 113 #4‐6, 8, 9, 17‐23 odd, 28, 30
Work with you partner to complete and turn
in Pg. 103 # 1- 18 Even. When you are
finished you can begin your homework.