Sometimes I see a pattern that I want to use but it's tricky to get the proportions right by eyeballing it. I want to show you a trick for doing just that. Both the old school and new way to do it.
I purchased a Dover book about Octagons - see the picture below. Dover books set up that any artist may use their images without worrying about copyrights. One of the octagons looks like it will be perfect for tangles. But there wasn't an example in the book that was the right size for my zendala tiles. The trick was to pull out my proportional scale. When I studied graphic design a few years ago this was a tool of the trade. We all had to figure out how to use it. As you can see below, my proportional scale has yellowed over the years.
To use a proportional scale you put in the dimensions of what you have and you rotate the tool until you see the dimension that you want it to be. You will then get a percentage that you then use for all the other dimensions to get your finished piece. Got that? Well, if that is as clear as mud, the web has come to the rescue There are now a variety of sites that you can use to do the exact same thing. http://www.staplesfineart.com/tools/propscale190809.html or http://scriptygoddess.com/resources/proportioncalc.htm or http://www.copyitmailit.com/p.htm These are just a few of several sites that do this for you. Use whichever one makes more sense to you.
By the way, feel free to use my template above in your work. If you right click on the picture you can copy the image.