1. Chapter 8
Similarity

2. Section 1 Ratio and Proportion

3. On the top of each assignment, write: your name the date
     New Homework procedure: 
                     effective 2/18/2019
On the top of each assignment, write:
your name
the date 
the section number of the assignment, for example 8.1 
As soon as you enter, take out your homework
If it is not out , you are responsible for showing it to me later.
Keep your assignment until you see it in gradebook.

4. Tues 19Feb19 Geometry Per 1 & 9
Agenda
New Homework Procedure
8.1 Ratio and proportion

5. Tues 19Feb19 Geometry Per 1& 9
Vocab
Ratio
Proportion
Cross-product
means/extremes
Reciprocal property

6. GOAL 1: Computing Ratios If a and b are two quantities that are measured in the same units, then the ratio of a to b is a/b. The ratio of a to b can also be written as a:b. Because a ratio is a quotient, its denominator cannot be zero. Ratios are usually expressed in simplified form. For instance, the ratio of 6:8 is usually simplified as 3:4.

7. Example 1: Simplifying Ratios

8. Example 2: Using Ratios The perimeter of rectangle ABCD is 60 centimeters. The ratio of AB:BC is 3:2. Find the length and width of the rectangle.

9. Example 3: Using Extended Ratios The measure of the angles in ∆JKL are in the extended ratio of 1:2:3. Find the measures of the angles.

10. Example 4: Using Ratios The ratios of the side lengths of ∆DEF to the corresponding side lengths of ∆ABC are 2:1. Find the unknown lengths.

11. GOAL 2: Using Proportions

13. Example 5: Solving Proportions

14. Example 6: Solving a Proportion Painting: The photo shows Bev Doolittle’s paint Music in the Wind. Her actual painting is 12 inches high. How wide is it?

15. Example 7: Solving a Proportion Estimate the length of the hidden flute in Bev Doolittle’s actual painting. (Note: in the photo, the flute is 1 7/8 inches long)

16. 1 ft = 12 in
1m = 1cm
1pound = 16 oz
1 mi = 5280
3 ft/4 in =(3 x 12)/4 =36/4 = 9/1

17. EXIT SLIP