# What's the difference between magnitude and pythagorean's theorem

## Main Question or Discussion Point

and what are the concepts of magnitudes..and how do we apply that in real life situations.

and what are the concepts of magnitudes..and how do we apply that in real life situations.
Magnitude just means "size" or "bigness" - so it can be used in many different situations.

Pythagoras' theorem just helps us to calculate magnitude in some situations:

If you imagine a graph with x going across and y going upwards, you can draw a line from the centre (where the axes cross at 0,0) to any point you like... for example the point 4,3 (x=4, y=3).

So if you then draw another line along the x axis to 4, and another up to the end of your line, you have drawn a triangle, and you can use pythagoras to find the length (the magnitude) of your line

magnitude2 = x2 + y2

= 42 + 32

= 16 + 9 = 25
so magnitude in this case is sqrt (25) = 5

you could use this to calculate the size of a piece of wood you would need on a gate, or something much more advanced.

hope this helps,
Michael

Magnitude (in terms of vectors) is simply an application of the Pythagorean theorem. It's more of a subcategory than a side-by-side comparison.

ah..so meaning magnitude is the application of pythagorean theorem...ahhh... makes sense..