# Pythagoras Theorem

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## Pythagoras Theorem

a2 + b2 = c2

Hypotenues = Longest side                                                                             To find the hypotenuse, add the squares of the other sides, then take the square root.

To find a shorter side, subtract the squares of the other sides, then take the square root.

If you know two sides of a right-angled triangle, you can find the third like this:

1. square (multiply by itself) the lengths you know
3. find the square root
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## Sin, Cos and Tan

In any right angled triangle, for any angle:

The sine of the angle = the length of the opposite side
the length of the hypotenuse

The cosine of the angle = the length of the adjacent side
the length of the hypotenuse

The tangent of the angle = the length of the opposite side
the length of the adjacent side

So in shorthand notation:
sin = o/h   cos = a/h   tan = o/a
Often remembered by: soh cah toa

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