How to calculate Phi with a ruler and protractor

I was searching through the file server looking for a paper written long ago and came across a drawing I had made for a "lunch and learn" after the deVinci Code came out.

The Golden Ratio Phi is 1.6180223....

Here's how to produce that value with simple geometry. This was done in Visio and uses a ruler to measure te distances.

The steps are easy:

1. Draw a right triangle with a base of 100 and the height of 50.
2. From the upper right apex of the triangle, use the protractor to inscribe an arc of radius 50.
3. Inscribe an arch from the lower left apex of radius where the first insscribed arc intersected the 50 radius on the connecting the upper right and lower left apexes.
4. The intersection of that arc and the line of length 100 divides that line into 61.8036 and 38.197 length.
5. That ratio is the Golden Ratio = 1.6180223577 ...