Page 86 - Math Course 3 (Book 2)

Triangle Congruence Postulates

SSS on the Coordinate Plane
WD = (–7 – (–5))² + (–4 – (–1))² Determine whether ΔABC ≅ ΔDEF for A(–5, 5),

B(0, 3), C(–4, 1), D(6, –3), E(1, –1), and F(5, 1).
= 49 + 9 or 13
A. yes
B. no
DV = (–5 –(1))² + (–1 – (–2))² C. cannot be determined

= 16 + 1 or 17
Answer
VW = (–1 –(-7))² + (–2 – (–4))²

= 36 + 4 or 40

ML = (4 – 1)² + (–7 – (–5))²

= 9 + 4 or 13

LP = (1 – 2)² + (–5 – (–1))²

= 1 + 16 or 17

PM = (2 – 4)² + (–1 – (–7))²

= 4 + 36 or 40

WD = ML, DV = LP, and VW = PM.
By definition of congruent
Answer segments, all corresponding
segments are congruent.
Therefore, ΔWDV ≅ ΔMLP by SSS

Your Turn!

Use SSS in Proofs
The two-column proof is shown to prove that △ABG ≅ △CBG if AB ≅ CB and AG ≅ CG. Choose the best
reason to fill in the blank.

Proof: B C
Statements Reasons
1. AB ≅ CB; AG ≅ CG 1. Given

2. BG ≅ BG 2. ______?______
3. ΔABG ≅ ΔCBG 3. SSS
A. reflexive B. symmetric
C. transitive D. substitution
G
A
Answer

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