Pythagoras in three dimensions
Pythagoras' theorem and trigonometry
Essential Mathematics Year 9
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Downloadable Lesson notes


  Learning objectives
  Recap of past learning
  Triangles are everywhere
  Finding the length of sides may require more than one calculation
  Using surds to make our life easier
  Example 1
  Example 2
  A challenging question
  Final words

This is another video in the Year 9 series looking at Pythagoras' Theorem and Trigonometry. Having already built the basics, I am now going to look at how we can apply Pythagoras' Theorem to three dimensional (3D) shapes. All you need to know is how to find a right angled triangle. Once you have identified it, you can mark the two sides you know and find the one you don't. I look at a number of common examples including a hemisphere (which I have seen used over and over again!) as well as explain that you might need to do more than one calculation in order to get the side length you need. As always, the explanations are clear and easy to understand and designed to help you smash maths.
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