1. Lesson 18 Ratio Word Problems Similar Triangles

2. Ratios & Proportions Ratio:compares two numbers –fractions! Proportions:compares two equivalent fractions

3. Solving Proportions Use cross products (cross-multiply) set the cross products equal to each other and solve

4. Example 18.1 The ratio of Arabians to mixed breeds in the herd was 2 to 17. If there were 380 horses in the herd, how many were Arabians?

5. Example 18.2 It took 600 kg of sulfur to make 3000 kg of the new compound. How many kilograms of other materials would be required to make 4000 kg of the new compound?

6. Similar Triangles two triangles with the same shape, same angles, but different side lengths corresponding sides: the sides opposite equal angles in similar triangles scale factor: the ratio that relates the sides of similar triangles

7. Example 18.3

8. Homework P.S. 18 1-20, 25-28