Objectives: To identify congruent polygons and their corresponding parts To use congruent polygons to determine missing measures

Congruent figures have the same size and shape.

Two polygons are congruent if and only if:

ALL their corresponding angles are congruent AND

ALL their corresponding sides are congruent

A CORRESPONDENCE is a matching up of the segments and angles of one polygon with the segments and angles of another polygon.

Determine if the two polygons below are similar. Explain.

Match the correspondence to write a congruence statement:

It is easier to determine

correspondence between angles. ABCD ≡ EFGH

ABCD ≡ EFGH

ALL Corresponding Angles ≡ ALL Corresponding Sides ≡

E

3

B 4 2 D 1 C 4

3

A

Decide whether the triangles are congruent. Justify your answers.

Statement

Reason

1. 2. 3. 4. 5. 6. 7.

1.2. 3. 4. 5. 6. 7.

Think: What two conditions MUSTbe met to show the ∆s congruent?

Statement

Reason

1. AC ≡ EC2. AB ≡ ED3. BC ≡ DC4. <A ≡ <E5. <B ≡ <D6. <1 ≡ <27.

1. Given.2. Given.3. Given.4. Given. 5. All rt. ≡6. Vert. ≡7. Def. of ≡

Polygons

Using Congruent Polygons to Determine Missing Measures

Find the missing measures, given ∆ DOG ≡ ∆ HSE :

H D 60

7 8 E 40

G O S 10

Homework Assignment:

Congruent Polygons WS, plus select problems from textbook: