1. 7-1 Ratios and Proportions Class Notes and Examples

2. Notes  A ratio is a comparison of two quantities using division.  i.e. For every 2 apples in my fridge, there are 4 oranges.  An extended ratio compares three or more quantities.  i.e. For every 2 apples in my fridge there are 4 oranges and 6 kiwi  After writing a ratio, reduce it as far as possible.

3. Example  1.) A pigmy rattlesnake has an average length of 18 in., while a Western diamondback rattlesnake averages a length of 5 ft 6 in. What is the ratio of the length of a pigmy rattlesnake to the length of a Western diamondback rattlesnake?

4. Notes  You can also use a given ratio to write and solve equations.

5. Examples  2.) The measures of two complementary angles are in the ratio of 1 : 3. What are the measures of the angles?

6. Examples  3.) The lengths of the sides of a triangle are in the extended ratio 2 : 4 : 5. The perimeter of the triangle is 77 in. What is the length of the longest side?

7. Notes  A proportion is an equation that shows that two ratios are equivalent, or equal.  If the proportion contains a variable, you can solve for it by cross multiplying (multiply the values on diagonal and set them equal to each other).

8. Notes 

9. Examples 

10. 