1. Pythagorean triples

3. A Pythagorean TRIPLE is any three integers which obey Pythagoras theorem.
These are just a few !

4. 3,4,5 triangle
Luckily for us, we do not need to learn all of them, just two of them and their multiples. The most important one is the 3,4,5

5. And its multiples

6. 5,12,13 triangle
Another important Pythagorean triple is the 5,12,13 triangle.

7. And its multiples

8. Problems which can come out in non-calculator maths!

10. Pythagorean triples in trigonometry !!!
Consider the following right angled triangle :
What is sin A ?
Since it is a special triangle, then the hyp = 5cm

11. Consider the following triangle :
What is tan A ?
Since it is a special triangle, the adj is 12

12. What if the triangle is not drawn?
In a right angled triangle,
What is
This means that the opp = 4cm and the hyp is 5cm
Therefore the adj = 3cm
So,