8-1 Ratios and Proportions

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8-1Ratios and Proportions

• Four Key Terms
• Two Properties

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Key Terms

1. Proportion

• A statement that two ratios are equal.

and
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Key Terms

1. Extended proportion

1. Written form of three or more ratios are equal.

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Properties of Proportions
Cross-Product Property

(1)
(2)
(3)
(4)
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Key Terms

1. Scale drawing
2. Scale

1. A drawing in which all lengths are proportional
   to corresponding lengths.
2. A comparison of each length in a drawing to the
   actual length.

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1 Answer the following

• A photo that is 8 in. wide and 10 in. high is
  enlarged to a poster that is 2 ft. wide and 2.5
  ft. high. What is the ratio of the height of the
  photo to the height of the poster?

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2 Write two equivalent proportions
(1)
(2)
(3)
(4)
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3a Solve each proportion
Cross-Product Property
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3b Solve each proportion
Cross-Product Property
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4 Find the dimensions of the scale drawing

• You want to make a new scale drawing with a scale
  of 1 in. 4 ft. What would be the dimensions of
  your 14 ft.-by-10 ft. bedroom in this scale
  drawing?