1. Goal: The learner will use proportions to find measures of objects.
Lesson 8.4

2. Scale: the ratio of the drawing to the actual measure.
Maps use a scale
For example: 1 inch = 150 miles

3. Using a Scale Drawing
Find the actual length of the car. Set up a proportion to solve.

4. Finding Ratios of Perimeters
A finished mural is to be 20 feet by 10 feet.
What is the perimeter of the drawing?
What is the perimeter of the mural?
Find the ratio of the drawing’s perimeter to the mural’s perimeter.

5. Finding Ratios of Area
Find the ratio of the area of the drawing to the area of the mural.

6. Perimeter, Area and Scale Drawings

7. Examples Ratio of Perimeters is What’s the scale ratio?
The ratio of the areas is

8. Assignment
P #3-5, 12, 13, 16, 17, 19, 20, 21, 28, 31, 33