I found some woodworking videos on how to find the center of a circle. I found a flaw in one of the methods; that's what this pair of applets is about. For reference, the videos are[br][url=https://www.youtube.com/watch?v=uzF3vwjFGSc]Davids Diy Reviews[/url][br][url=https://www.youtube.com/watch?v=UUL24IdUrkU]Tomahawk DIY[/url]

The first applet resembles the second method from the Davids Diy Reviews video. If you are eyeballing the placement of the two corners--even if you've made sure they cross the circle at the same distances from their vertices--you might not get a perfect square. It looked to me like the example in the video suffered from this effect a little.

I suspect that the above method was a modification of something like the first method shown in the Tomahawk DIY video. [i]That[/i] method really does work, but wastes some effort. An inscribed right angle is subtended by a semicircle, so the latter method produces two short chords [i]and a diameter[/i] with each placement of the corner.[br][br]It is not necessary to align these diameters so that the two corner placements create a square. The next applet shows what happens if you just draw two inscribed right angles and the chords where they cross the circle (these chords being diameters).

Well, now YouTube thinks I want more videos about finding the center of a circle. I thought [url=https://www.youtube.com/watch?v=xkkIziKDGt4]this one by Heartwood Art[/url] was quick and clever.