Math Is Fun Forum

Master Foo Ling Yu's philosophy around the punch bowl:
Man who stick nose in punch, gets punch in nose.

SIMPLE LOGIC:
Q: Why should you never go out into the jungle between 2pm and 4pm?
A: Because elephants are falling out of the trees.
Q: Why are Pygmies so small?
A: Because they went out into the jungle between 2pm and 4pm.

OK. Let us take a trip to the bowling alley, shall we? Now how many pins are set up? Usually 10! That's right. How many rows are there? Four. We know that 1+2+3+4=10. Ten is a triangle number. What is its triangle root? 4! Did you know that 666 is a triangle number? Yikes! Its triangle root is 36. Why? Because if you add the numbers from 1 to 36, you will get the sum of 666.
Wikipedia has an article on triangle numbers. At the very bottom, they give a formula for testing if a number is a triangle number. If it comes out as a whole integer, it is a triangle. If it comes out with numbers right of the decimal, it is NOT. The same idea would apply for a square root. If I placed a number in the square root sign, and it came out a whole integer, it's a square number. If it has numbers right of that decimal point, it ain't.
My forum http://forums.delphiforums.com/figurate/start also goes into more details.

You may also want to look at the math books of the late Dr. Lancelot Hogben. Very valuable for all ages and all levels of understanding. I have some book lists at my forum that point to him, among other great minds.

http://forums.delphiforums.com/figurate/start

Yes, we know about the cube root. How about the tetrahedron root, octahedron root, etc;? The extracting of 3D figurate numbers is what has me stumped. I'm glad you like my forum.

Please consider visiting our forum. Please let me know if their is any way I can contribute to yours. Say, as you may well be aware, just as one can generate square numbers (n x n), one can also generate triangle numbers. Where any of you aware that just as there is a square root,  there is also a triangle root? I'm not kidding.