Concept 1. Example 1 Use SSS to Prove Triangles Congruent Write a flow proof. Prove:ΔQUD ΔADU...

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Use SSS to Prove Triangles Congruent

Write a flow proof.

Prove: ΔQUD ΔADU

Given: QU AD, QD AU ___ ___ ___ ___

Use SSS to Prove Triangles Congruent

Answer: Flow Proof:

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

Which information is missing from the flowproof?Given: AC AB

D is the midpoint of BC.Prove: ΔADC ΔADB

___ ___

A. AC AC

B. AB AB

C. AD AD

D. CB BC

___ ___

___ ___

___ ___

___ ___

EXTENDED RESPONSE Triangle DVW has vertices D(–5, –1), V(–1, –2), and W(–7, –4). Triangle LPM has vertices L(1, –5), P(2, –1), and M(4, –7).a. Graph both triangles on the same coordinate

plane.b. Use your graph to make a conjecture as to

whether the triangles are congruent. Explain your

reasoning.c. Write a logical argument that uses coordinate

geometry to support the conjecture you made in

part b.

Triangle DVW has vertices D(–5, –1), V(–1, –2), and W(–7, –4). Triangle LPM has vertices L(1, –5), P(2, –1), and M(4, –7).

Triangle DVW has vertices D(–5, –1), V(–1, –2), and W(–7, –4). Triangle LPM has vertices L(1, –5), P(2, –1), and M(4, –7).

Triangle DVW has vertices D(–5, –1), V(–1, –2), and W(–7, –4). Triangle LPM has vertices L(1, –5), P(2, –1), and M(4, –7).

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

1. A

2. B

3. C

A. yes

B. no

C. cannot be determined

Determine whether ΔABC ΔDEF for A(–5, 5), B(0, 3), C(–4, 1), D(6, –3), E(1, –1), and F(5, 1).

Use SAS to Prove Triangles are Congruent

ENTOMOLOGY The wings of one type of moth form two triangles. Write a two-column proof to prove that ΔFEG ΔHIG if EI HF, and G is the midpoint of both EI and HF.

Use SAS to Prove Triangles are Congruent

Prove: ΔFEG ΔHIG

Given: EI HF; G is the midpoint of both EI and HF.

1. Given1. EI HF; G is the midpoint ofEI; G is the midpoint of HF.

Proof:ReasonsStatements

A. A

B. B

C. C

D. D

1.

ReasonsProof:Statements

1. Given

Use SAS or SSS in Proofs

Write a proof.

Prove: Q S

Use SAS or SSS in Proofs

1. Given

ReasonsStatements

A. A

B. B

C. C

D. D

Choose the correct reason to complete the following flow proof.

A. Segment Addition Postulate

B. Symmetric Property

C. Midpoint Theorem

D. Substitution