There are three SUMS Lesson Introductions for this topic. They are described below. Each opens in its own page so that you can link them directly into your lesson material.
For many thousands of years people have needed to build homes and grander structures. This means that they needed to be able to make accurate calculations of the distance from one point to another in a building, for example to ensure that roof timbers were cut to the correct length. Pythagoras was famous for many things, with mathematics being just one part of his work. The 'Theorem of Pythagoras' is simple to learn and apply.
The lesson introduction is based on the SUMS Math interactive activity 'Pythag' from the main SUMS Math set.
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This is a simple introduction to what the Theorem says, using a 3,4,5 triangle as an example.
http://www.sums.co.uk/lessons/trig1/trig1a
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Lesson 2. Using Pythagoras to find the hypotenuse.
This lesson shows the method for using Pythagoras to calculate the hypotenuse (longest side) of a right-angled triangle when the other two sides are known.
http://www.sums.co.uk/lessons/trig1/trig1b
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Lesson 3. Using Pythagoras to find any side.
This lesson shows the method for using Pythagoras to calculate a missing side when it is not the hypotenuse.
http://www.sums.co.uk/lessons/trig1/trig1c
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