C.a.R. >
Applications >
Similarity and Angles>
**Golden Ratio**

Here, you can see how the Golden Ratio is constructed. You
can operate the green keys like a cassette player.

The construction works, since QB=AP. The circle has radius
QB/2. Using the chord tangent theorem
one sees QA*QP=QB^2. Thus QP is
split in the Golden Ratio. Therefore, QC splits QB in the Golden Ratio too.

### Technical Information

This is a special form of an applet, using keys to walk
through a construction. It is possible, to set break points to stop only at
certain interesting construction steps.