User talk:Elfman12345

In the article of Pythagorean theorem in three dimensions, it goes on about using the Pythagorean theorem (generally and simply Known as) ((A^2+B^2=C^2) or (C^2=A^2+B^2) the square of the hypotenuse (the longest side) equals the sum of the square of the other two sides)). indicated by the lengths used (BD^2=BC^2+CD^2) or (BC^2+CD^2=BD^2) then (AD^2=AB^2+BD^2) so uses the theorem Twice to calculate the length of the diagonal in a cube. Then it goes on to do this in one step: Being (AD^2=AB^2+BC^2+CD^2) (which is hard to follow and looks clumsy and cumbersome) Well when I was a 13Y/O I did this in a year 9 (form 3 in Australia) maths test. but instead of lengths (AD^2=AB^2+BC^2+CD^2) which is (AB^2+BC^2+CD^2=AD^2) I used side "A" instead of Length "AB" Side "B" instead of Length "BC" side "C" instead of length "CD" and for the Diagonal I used a "D" instead of length "AD" So we have the original Pythagorean theorem (A^2+B^2=C^2) or (C^2=A^2+B^2) the square of the hypotenuse (The Longest side) equals the sum of the square of the other two sides.

Now we can say (A^2+B^2+C^2=D^2) or (D^2=A^2+B^2+C^2) which is the square of the diagonal (the longest distance between two corners) is equal to the sum of the square of the other THREE sides.

Thus a three dimensional Pythagorean theorem written and expressed in its original and simplest form, as it was meant to be. (A^2+B^2+C^2=D^2)

If you go to You Tube "SAT Maths Short cut, Huge time saver: Longest Diagonal Question", or "How to find the diagonal of a cube" I have left comments there a few months ago, explaining the simplified 3D Pythagorean theorem.

Cheers Elfman12345 (Terry)