Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
4. Proving Statements about Segments and Angles
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Exercise 49 Page 476

What can we conclude using the Transitive Property of Congruence?

x=1, see solution.

Practice makes perfect

Let's take a look at the diagram.

It is given that QR is congruent to PQ, that RS is congruent to PQ, that QR=2x+5, and that RS=10-3x. Statement1)& QR≅ PQ, RS≅ PQ, & QR= 2x+5, RS= 10-3x Reason1)& Given Since both QR and RS are congruent to PQ, by the Transitive Property of Congruence QR and RS are also congruent segments. Statement2)& QR≅ RS Reason2)& Transitive Property of Congruence Recall that two segments are congruent if and only if they have the same length. Therefore, since QR and RS are congruent segments, we know that they have the same length. Statement3)& QR= RS Reason3)& Definition of Congruent Segments Finally, the value of x can be found by using the Properties of Equality.
QR=RS
2x+5= 10-3x
â–Ľ
Solve for x
2x=5-3x
5x=5
x=1
We found that x=1. Finally, we will write the steps we just took as a two-column proof.
Statements
Reasons
1.
QR≅ PQ, RS≅ PQ, QR=2x+5, RS=10-3x
1.
Given
2.
QR = PQ, RS=PQ
2.
Definition of congruent segments
3.
QR=RS
3.
Transitive Property of Equality
4.
2x+5=10-3x
4.
Substitution Property of Equality
5.
5x+5=10
5.
Addition Property of Equality
6.
5x=5
6.
Subtraction Property of Equality
7.
x=1
7.
Division Property of Equality