Math Is Fun Forum

Take my thread.
(late)

There is.
This follows immediately from the fact that the volume of a pyramid is exactly 1/3 of the volume of the prism, which can be proved by suitable disection of the prism into 3 pyramids, which must have equal volumes by the Cavalery (the name may be spelled incorrectly) principe.

.... which is exactly:

Not so fast!
if x is integer, then

"Creative"?
What do you mean?
(give an example of some "creative" names)

You already know the Pythagorean's.
Good.

And devz?
this sounds good...
devz?

Absolutely right.
Graphically:

But sorry. If you don't like my comments, I'll stop posting.

OK I'll try another.
Using:
M=A+C
N=B+D
Q=A+D
P=B+C
S=A+B+C+D

We have:M+N+Q+P=A+C+B+D+A+D+B+C= (A+B+C+D)+(A+B+C+D)=2S.
So M+N+Q+P=2S should be right.
But if you pick some values for M,N,Q,P and S, for which 
M+N+Q+P=2S
is false, then the system will have no solutions for the chosen M,N,Q,P and S.
clear now?