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Chapter Seven
Proportions and Similarity
Term | Definition |
---|---|
ratio | a comparison of two quantities using division. |
Extended ratios | can be used to compare three or more quantities, example a:b:c |
proportion | an equation stating that two ratios are equal |
extremes | In the proportion a/b=c/d, a and d are the extremes |
means | In the proportion a/b=c/d, b and c are the means |
cross products | the product of the extremes ad and the product of the means bc are the cross products |
Cross Products Property | In a proportion, the product of the extremes equals the product of the means. |
Equivalent Proportions | a/b=c/d, b/a=d/c, a/c=b/d, c/a=d/b |
Similar Polygons | Two polygons are similar IFF their corresponding angles are congruent and corresponding side lengths are proportional. Their shape is the same, but not necessarily their size. |
Similarity Ratio | The scale factor between two similar polygons |
Scale Factor | the ratio of the lengths of corresponding sides of two similar polygons. It depends upon the order of comparison. |