Chapter 7 Study Guide Grayson

1. (7-1) Ratios and Proportions
a. Define Ratios, extended ratios, proption
i. Ratio – a comparison of two quantities using division ii. Extended ratio – can be used to compare three or more quantities iii. Proportion – an equation stating two ratios are equal
b. Apply the Cross Products Property
i. If a/b = c/d when b is not = to 0 and d is not = to 0, then ad=bc
c. Be able to write ratios
d. Write and solve proportions.
e. Answer p. 525 #9-14 (ON SEPARATE PAPER)
2. (7-2) Similar
a. Define similar polygons, scale factor
i. Similar polygons – have the same shape but not necessarily the same size ii. Scale factor – the ratio of the lengths of the corresponding sides of two similar polygons
b. Use proportions to identify similar polygons.
c. Solve problems using the properties of similar polygons
d. Use scale factors and proportions to solve problems involving similar figures
e. State the Perimeters of Similar Polygons Theorem
i. If two polygons are similar, then their perimeters are proportional to the scale factor between them.
f. Answer p. 525 #15-18 (ON SEPARATE PAPER)
3. (7-3) Similar Triangles
a. State the Angle-Angle (AA) Similarity
i. If two angles of one triangle are congruent to two angles of another triangle. Then the triangles are similar.
b. Identify similar triangles using the AA similarity postulate and the SS and SAS Similarity Theorems.
c. State the Triangle Similarity Theorems.
i. SSS- if the corresponding side