1. 7.5(A) Generalize the critical attributes of similarity, including
ratios within and between similar shapes. Also addresses 7.5(C).
Mathematical Processes
7.1(A), 7.1(B)

2. Determine the length of each object on a scale drawing with the given scale. Then determine the scale factor.
1. a subway car 34 feet long; 1 inch = 5 feet
2. a table 1.5 meters long; 3 centimeters = 0.25 meters
3. The distance between New York City and Washington, D.C., is 3.75 inches on a map of the United States. The scale on the map is 1 inch to 90 miles. How far is Washington, D.C., from New York City?

3. Answers 1.
2. 18 cm; mi

4. HOW can proportional
relationships be applied to geometry?

5. • to identify similar figures
• to determine missing measures in
similar figures

6. • similar figures

7. Identify Similar Figures
Words If two figures have congruent corresponding angles and the ratios of their corresponding sides are equivalent, then they are similar.
Model
Symbols

8. Determine Missing Measures
If you know that two figures are similar, you can determine missing measures.
Words If two polygons are similar, then
• their corresponding angles are congruent and
• the ratios of their corresponding sides are equivalent.
Model
Symbols
You can use a proportion or the scale factor to determine the measure of the sides of similar figures when some measures are known.

9. HOW can proportional relationships be applied to geometry?

10. HOW can proportional relationships be applied to geometry?
Sample answers:
By checking the ratios between and within figures to identify whether or not they are similar figures.
By using a proportion or scale factor to determine the missing measure of the sides of similar figures.

11. Write what you know about the corresponding angles and sides of two similar figures.