7th Grade Math

306 Proportions and Similarity

Chapter Study

Guide and Review

Key Concepts

Proportions (Lesson 1)

• If two related quantities are proportional, then
  they have a constant ratio.


• The cross products of a proportion are equal.

Scale Drawings (Lesson 2)

• Scale drawings are used to represent objects that
  cannot be drawn at actual size.


• The scale is a ratio of a drawing’s measurement to
  an object’s measurement.

Similar Figures (Lesson 3)

• If figure B is similar to figure A by a scale factor,
  then

perimeter of

figure B

= perimeter of

figure A

· scale factor

area of

figure B

= area of

figure A

· (scale factor)^2

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a

b

Be sure the following

Key Concepts are noted

in your Foldable.

Key Vocabulary

corresponding angles

corresponding sides

cross products

equivalent ratios

indirect measurement

nonproportional

proportion

proportional

rate

scale

scale drawing

scale factor

scale model

similar figures

unit rate

Vocabulary Check

Choose the term from the list above that best

matches each phrase.

1. two quantities that have a constant rate or
   ratio


2. a scale written as a ratio in simplest form
   without units of measurement


3. an equation that shows that two ratios or
   rates are equivalent


4. a ratio of two measurements with
   different units


5. a rate that is simplified so that it has a
   denominator of 1


6. two ratios that have the same value


7. the ratio of the distance on a map to the
   actual distance


8. figures with the same shape


9. a relationship in which the ratio is not
   constant

and NonportionalProportional

Relationships

Rates

Solve Proportions

Scale Dreawigs

Similar Figures

and Area ofPerimeter

Similar Figures

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