| A | B |
|---|
| Arithmetic Mean of a and b | ½(a + b). |
| Enlargement | A dilation that has a scale factor k > 1. |
| Geometric Mean of a and b | The positive number x such that a/x = x/b. |
| Proportion | An equation that equates two ratios. |
| Ratio | If a and b are two quantities that are measured in the same units, then the ratio of a to b is a/b. (Can also be written as a:b.) |
| Reduction | A dilation that has a scale factor k, 0 < k < 1. |
| Scale Factor | The ratio of corresponding linear measures in two similar polygons or two similar solids. |
| Similar Polygons | Two polygons whose corresponding angles are congruent and the lengths of corresponding sides are proportional. |
| Dilation | A transformation with center C and scale factor k that maps every point P in the plane to a point P', so that 1.) If P is not point C, then CP is coincident with CP', and CP' = k(CP), where k > 0 and k not = 1. 2.) If P is point C, then P = P'. |
