Designing with Proportions  What is proportionality?  How do you use a scale factor to create proportionality?

What is a Proportion?  An equation stating that two ratios are equal.

What does proportional mean?  Having the same or a constant ratio  Are the four sides of these quadrilaterals proportional?

Scale Factor  When you compare corresponding measurements of proportional objects, you get a ratio.  This ratio is called the scale factor.

How are scale factors used? (sample student answers)  Maps  Models  Drawings  Movie miniatures

Are dolls and action figures accurate models?  Are their measurements proportional to real people?  Are they proportional to the environment that they live in?

How do reality and imagination coexist?

Your Goal:  Design a doll or action figure  Create an environment in which that character would live (dream house, secret lair, vacation motor-home, etc.)  Decide how tall your character would be in real life and how tall its figurine would be. Use these measurements to create a scale factor.

Math Man and his Magical Mathematical Mansion! Scale Factor: 6 inches = 7 feet Simplifies to: 1 inch = 1 1/6 feet Scale Factor: 6 inches = 7 feet Simplifies to: 1 inch = 1 1/6 feet