Practice problems for scale factors:

If a certain shape is increased or decreased by the scale factor given both horizontally and vertically to give a similar figure, What is the resulting length of a diagonal line, and what is the resulting area?

scale factor (horizontal and vertical)	original diagonal length	original area	new diagonal length	new area
1	8 cm	7 cm2
2	9 cm	9 cm2
3	6 cm	8 cm2
1/2	6 cm	12 cm2
5	2 cm	3 cm2
1/3	18 cm	18 cm2

6 cm

9 cm2

12 cm

8 cm

10 cm2

90 cm2

3

5 cm

12 cm2