CK-12 Geometry-Concepts

http://www.ck12.org Chapter 4. Triangles and Congruence

CK-12 Foundation: Chapter4CreatingCongruenceStatementsB

Concept Problem Revisited

If 4 ABC∼= 4 XY Z, thenBA∼=Y Xand^6 C∼=^6 Z.

Vocabulary

To becongruentmeans to be the same size and shape. Two triangles arecongruentif their corresponding angles
and sides are congruent. The symbol∼=meanscongruent.

Guided Practice

1. If 4 ABC∼= 4 DEF, what else do you know?


2. If 4 KBP∼= 4 MRS, what else do you know?


3. If 4 EW N∼= 4 MAP, what else do you know?

Answers:

1. From this congruence statement, we know three pairs of angles and three pairs of sides are congruent.^6 A∼=

(^6) D, (^6) B∼= (^6) E, (^6) C∼= (^6) F,AB∼=DE,BC∼=EF,AC∼=DF.

2. From this congruence statement, we know three pairs of angles and three pairs of sides are congruent.^6 K∼=

(^6) M, (^6) B∼= (^6) R, (^6) P∼= (^6) S,KB∼=MR,BP∼=RS,KP∼=MS.

3. From this congruence statement, we know three pairs of angles and three pairs of sides are congruent.^6 E∼=

(^6) M, (^6) W∼= (^6) A, (^6) N∼= (^6) P,EW∼=MA,W N∼=AP,EN∼=MP.
Explore More
For questions 1-4, determine if the triangles are congruent using the definition of congruent triangles. If they are,
write the congruence statement.

1.

2.

3.