Find the value of each expression.

a. 1.6 – 0.3 0.4 + 2.6 b. 4.5 – 0.024 + 1.8 – 0.36

COURSE 1 LESSON 8-6

4.08 5.916

Congruent and Similar Figures

8-6

In Lesson 8-5 You learned to identify regular

polygons and to classify quadrilaterals.

What You Learned

Review

8-6

4.2.6 A.3 Identify similar figures.

pg 392-395

Pg 124-125 Daily Notetaking Guide

Materials:

Standards:

Materials

In Lesson 8-6 To identify congruent and similar

figures.

What You’ll Learn

Why Learn This?

Designers use congruent figures in architecture.

You can fit some congruent figures together without

gaps or spaces..

Introduction

Vocabulary

Congruent figures have congruent corresponding

sides and congruent corresponding angles. The

matching sides and angles are corresponding

parts.

Similar Figures – are figures that have the same

shape but not necessarily the same size.

Vocabulary

Congruent Figures – are figures that have exactly

the same size and shape.

COURSE 1 LESSON 8-6

Congruent and Similar Figures

(For help, go to Lesson 8-3.)

Classify each triangle by its sides.

1. How can you tell that two angles are congruent?

8-6

Vocabulary Review

They have the same measure.

2. 3

two congruent

sides: isosceles

no congruent

sides: scalene

Are the pentagons congruent?

COURSE 1 LESSON 8-6

The corresponding sides and angles are congruent,

so the pentagons are congruent.

Congruent and Similar Figures

8-6

Quick Check

Which triangle appears to be similar to HJK? Confirm

your answer by finding whether the corresponding sides are

proportional.

COURSE 1 LESSON 8-6

a.

b.

=

Similar

4

2

6

3

=

Not similar

/ 4

20

6

25

Congruent and Similar Figures

8-6

Quick Check

Are the figures congruent or similar? Explain.

COURSE 1 LESSON 8-6

The two rectangles are not congruent because

their corresponding sides are not congruent.

The two rectangles are similar because their corresponding

sides are proportional and their corresponding angles are congruent.

Congruent and Similar Figures

8-6

Quick Check

How do you identify similar figures?

Similar figures have congruent corresponding

angles and proportional corresponding sides.

Closure

Tell whether the figures are congruent or similar.

1. 2.

COURSE 1 LESSON 8-6

similar congruent

Congruent and Similar Figures

8-6

Class work

Work

pg 394 – 395 1 - 24

Homework

pg 369 Practice 8-6

pg 370 Guided Problem Solving 8-6

Work