Words

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Words to Review Give an example of the vocabulary word. Ratio

Proportion

3

or 3 : 2 2

6 3



x 5

Extremes

Means

The first and last terms of a proportion. The extremes of

The middle terms of a proportion. The means of

a c



are a and d. b d

a c



are b and c. b d

Geometric mean

Similar polygons

For two positive numbers a and b, the positive number x

ABDC ⬃ EFHG F

B E

a x such that



, or x b

A

苶. x  兹a pb

G

C

Scale factor F

P

2

4

E

A

5

3

G

8

2 P

1

C

10

C

D

Dilation

B

6

H

4

H

D

The scale factor of ABDC to 2 EFHG is

. 1

Dilation with scale factor k  2.

Words to Review • Geometry Notetaking Guide

185

Mtgnt_08 trans wk bk 11/3/03 3:43 PM Page 186

Reduction P

Enlargement 2 P

P 1

C

Reduction with scale factor 1 k 

. 2

2 P

1

C

Enlargement with scale factor k  2.

Review your notes and Chapter 8 by using the Chapter Review on pages 516–518 of your textbook.

186

Geometry Notetaking Guide • Chapter 8