7.1
Ratios:
- A Ratio is a comparison of a number a and a nonzero number b using division. They can be written in Four different ways. Ratios are usually written in Simplest form.
Proportions:
- An Equation that states two ratios are equal is called a Proportion. In a proportion the numbers b and c are called the Means of the proportion. The number a and d are called the Extremes of the proportion.
Cross Product Property:
- In a proportion the product of the extremes is equal to the product of the means.
7.2
Similarity:
- Two figures that have the same Angles are Congruent AND corresponding side lengths are Proportional THEN two polygons are Similar Polygons.
Scale Factor:
- If the two polygons are similar THEN the ratio of the lengths of two Corresponding sides is called the Scale Factor.
Determining Similarity:
- Check that corresponding angles are Congruent.
- Check whether corresponding side lengths are Proportional.
7.3
Angle-Angle Similarity Postulate:
- If two angles of one triangle are Congruent to two angles of another triangle THEN the two triangles are Similar
