Geometric proof of the dot product

This is a geometric proof of the dot product that I submitted to Mathematics Magazine for the "Proof without words" section. They rightly rejected it because it's only valid for the first quadrant. Cynthia and I tried to rework it for the other quadrants but it lost its elegance so we gave up.

(Oldish) images of my house

These are nice pics that Bruce and Anne had taken of my house soon after it was completed.

Tutorials #10, #11, #12, #13

Tutorials #10, #11, #12, #13 are now posted on happyfuncoding.com

Enjoy.

Tutorial #9 -- arrays

Euler's equation

Vector Projection Demo

Use your mouse to move around vector A

Happyfuncoding Tutorial #8 -- for loops