1. Green Living
Lesson #3

2. Learning Intentions
Solve problems using ratio and scale factors in similar figures
Learn about Wind Farms as an aspect of “Green Living”

3. Wind Farms

4. Think, pair, share What do you think you know about wind farms?
How do you think wind farms work?
What do you think you know about wind turbines?

5. Share

6. More facts...
Wind turbines convert kinetic energy into mechanical power.
A generator converts mechanical power into electricity.
The wind turns the blades which spin a shaft, which connects to a generator and makes electricity.

7. Waubra Wind Farm 1 turbine has a capacity of 1.5MW
128 turbines have a capacity of ...
192 MW
They provide electricity for 143,000 households
They offset 635,000 tonnes of greenhouse gas emissions every year

8. In Australia
Green electricity from wind helps Australia cut greenhouse emissions by 3,256,000 tonnes per year
Equivalent to taking 752,000 cars off our roads or planting million trees (Future Energy)

9. Calculate
Australia offsets 3,256,000 tonnes of greenhouse gas emissions per year
= 752,000 cars off our roads
= 4.86 million trees planted
Waubra offsets ,000 tonnes of greenhouse gas emissions per year
= ? cars off our roads
= ? trees planted

10. Explore
Wind turbines are very big

11. Think, group, share
How can we measure their height?

12. Share

13. Collect data Choose a tall object eg. tree or flag-pole
Measure height of student
Measure distance from looker to student
Measure distance from looker to object
Record several accurate measurements
Record for more than one object
Calculate height of objects

14. Share

15. Similar Triangles

16. Definition & Properties
Triangles are similar if they have the same shape, but can be different sizes.
They are still similar even if one is rotated, or one is a mirror image of the other.
Corresponding angles are congruent (same measure) (AAA).
Corresponding sides are all in the same proportion (SSS).
Two pairs of sides in the same proportion and the included angle equal (SAS)

17. Understanding
If you know the height of the wind turbine, where would I be standing?

18. Worksheet

19. Conclusion
What other applications could I use similar figures, ratios and scale factors?

20. Reflection
Rate your understanding of similar triangles and ratios on a scale of 1-5.
What can you do to improve your understanding?
What would you like to know more about wind turbines or similar figures?

21. References
Acciona Australia. (2013) Waubra wind farm. Retrieved April 10th, from divisions/energy/operational-projects/waubra-wind-farm
Future Energy. (2009). Facts and stats. Retrieved April 10th, from
EDinformatics. (1999). How wind turbines work. Retrieved April 10th, from how_wind_turbines_work.htm
Math Open Reference. (2009). Similar triangles. Retrieved April 10th, from
Cowens, John. (2013). Measure a tree. Retrieved April 10th, from cowens