How does Pythagoras Theorem work?

The Pythagoras Theorem only works with right-angled triangles. If you see a triangle other than right-angled triangles, then you do not need to apply the Pythagoras Theorem. The right-angled triangle has three sides, as with all triangles, and they are all labelled. One side is known as the hypotenuse (the longest side). The other two are known as the adjacent and the opposite. These two labels are determined by where the angle is but this is irrelevant when determining the length of a side using Pythagoras Theoream. The equation for the Pythagoras Theorem is a(squared)=b(squared)+c(squared). The a is the length of the hypotenuse. So you can find the length of the hypotenuse squared by squaring and adding the length of both the adjacent and opposite sides of the right-angled triangle. And to find the opposite or the adjacent length, you just rearrange and this is quite simple.