1. Perimeters and Areas of Similar Figures
Geometry 8-6

2. Get your supplies
Graph Paper
Exploration

3. Exploration Draw a Rectangle on your graph paper
Calculate its area (in graph units)
Exploration

4. Multiply each dimension of the rectangle by a scale factor and draw the new larger (smaller) rectangle
Calculate its area
Exploration

5. Exploration What is the ratio of the side lengths?
What is the ratio of the areas?
How many smaller rectangles would it take to fill the larger rectangle?
Exploration

6. Exploration 108 12 Calculate the area of these two similar triangles
What is the ratio of the side lengths?
What is the ratio of the areas?
Exploration

7. Calculate the area of these two circles is terms of pi9π 4π
What is the ratio of the radii?
What is the ratio of the areas?
Exploration

8. If corresponding side lengths of two similar polygons or the radii of two circles compare in the ratio a/b, then the areas compare in the ratio a2/b2.
Proportional Area

9. Example

10. Example

11. Example

12. Example

13. Practice

14. Practice

15. Practice

16. Practice

17. Practice

18. Practice

19. Practice

20. Practice

21. Practice

22. Sample Problems

23. Sample Problems

24. Sample Problems

25. Sample Problems

26. Sample Problems

27. Sample Problems

28. Sample Problems

29. Sample Problems

30. Pages 456 – 459
2-18 even, 26, 36, 39, 50, 51
Homework