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Catalyst: Measuring our coastline

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Two people stand on clifftop with ocean in the background
Catalyst: Measuring our coastline

SUBJECTS:  Geography, Maths

YEARS:  5–6


How long is the Australian coastline?

See Dr Derek Muller and Simon Pampena discussing the perimeter of the Australian coastline. Find out how the accuracy of that measurement depends on the length of the 'measuring stick' used. They discuss how a coastline is much like a fractal such as 'Koch's Snowflake'!


Things to think about

  1. 1.What is the difference between perimeter and area? How could we measure the perimeter of a rectangle, a classroom, or school? What about the coastline of Australia?
  2. 2.How long is the Australian coastline? Dr Derek Muller speaks of two estimates. What does he say about the length of the 'measuring stick' when he explains the huge difference between them? Listen to Simon Pampena liken the coastline to a fractal. What do we see as we magnify a fractal?
  3. 3.Find a map of Australia in an atlas, or print out one from the internet. Make sure it has a scale. Measure its perimeter first with a ruler, then with string. Use the map's scale to convert both measurements to kilometres (km). For example, if the scale is 1 cm = 500 km, multiply your measurement in cm by 500. Explain your results, including reasons for any differences between the two.
  4. 4.Locate and gather images of fractals, including an example of 'Koch's Snowflake'. Make your own fractal by drawing a large equilateral triangle with 15-cm sides. Draw three smaller equilateral triangles along each of the three sides. Repeat that for each of these triangles. Add colour to make interesting patterns.


Acknowledgements

Image credit: 'Cape St George_32_January 05_2010', courtesy Michael Dawes (Flickr)



Date of broadcast: 31 Mar 2011


Copyright

Metadata © Australian Broadcasting Corporation and Education Services Australia Ltd 2012 (except where otherwise indicated). Digital content © Australian Broadcasting Corporation (except where otherwise indicated). Video © Australian Broadcasting Corporation (except where otherwise indicated). All images copyright their respective owners. Text © Australian Broadcasting Corporation and Education Services Australia is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0).

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