Lesson 7

Lesson 7 Summary

 

You started this lesson by looking at the different versions of the Rubik’s Cube. (For more review about the Rubik’s Cube, you can turn to page 506 of the textbook.)

 

In Math Lab you gathered evidence that further supported the relationships between the surface area and volume of similar 3-D objects. You discovered that the surface area of a similar object is related to the original object by the square of the scale factor (k2). The volume of a similar object is related to the volume of the original object by the cube of the scale factor (k3). These relationships can be stated as shown.

 

 

If you know the surface areas or volumes of two similar objects, you can determine the scale factor that relates their dimensions. The scale factor is the square root of the ratio of the surface areas, or the cube root of the ratio of the volumes, of the two similar objects.

 

In Lesson 8 you will use the relationships you have identified to solve problems involving scale factor and 2-D shapes or 3-D objects.