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chapter 6.1-6.3
math
Term | Definition |
---|---|
ratio of a to b | a comparison of two numbers using division. the ratio of a to b, where b is not equal to 0, can be written as a to b, as a:b, or a over b |
proportion | an equation that states that two ratios are equal |
means | the middle term |
extremes of a proportion | the first and last terms of a proportion |
cross products property of a proportion | in a proportion, the product of the extremes equals the product of the means |
geometric mean | for two positive numbers a and b, the positive number x that satisfies a/x = x/b. so x^2 = ab and x=sq.root ab |
additional properties of proportions 2.reciprocal property-if two ratios are equal, then their reciprocals are also equal | 3. if you interchange the means of a proportion, then you form another true proportion 4.in a proportion, if you add the value of each ratios denominator to its numerator, then you form another true proportion |
scale drawing | a drawing that is the same shape as the object it represents |
scale | a ratio that describes how the dimension is a scale drawing are related to the actual dimensions of the object |
similar polygons | two polygons such that their corresponding angles are congruent and the lengths of corresponding sides are proportional |
scale factor | the ratio of the lengths of two corresponding sides of two similar polygons |
perimeters of similar polygons theorem | if two polygons are similar, then the ratio of their perimeters is equal to the ratios of their corresponding side lengths. |
corresponding lengths in similar polygons | if two polygons are similar, then the ratio of any two corresponding lengths in the polygons is equal to the scale factor of the similar polygons. |