Vocab Chapter 7
1. Ratio: comparison of two numbers, often by division a/b or colon a:b
2. Proportion: an equation where two ratios are equal.
3. Cross Product: the products "ad" and "bc" from the proportion
4. Similar: same shape, not necessarily same size ~
5. Congruent: exact same shape, exact same size
6. Similar Polygons:
(1) corresponding angles are congruent and
(2) corresponding sides are proportional.
7. Similarity Ratio: The ratio of the lengths of corresponding sides.
8. Golden Rectangle: A rectangle that can be divided into a square and a rectangle that
is similar to the original rectangle.
9. Golden Ratio: The length and the width of any golden rectangle is 1.618 : 1
10. Indirect Measurement: The use of similar triangles and measurements to find
distances that are difficult to measure directly.
11. Means of proportions: b and c
12. Extremes of proportions: a and d
13. Geometric Mean: Proportions in which the means are equal.