Tuesday, October 12, 2010

Trigonometry for Dummies?

My poor daughter was pulling her hair out last night and this morning because she has a big Trigonometry test today. After giving her the usual "good mom" advice about keeping up better on the homework and getting help before the test I hugged her and said "I remember those days. Do you suppose they make a Dummies book for Trigonometry?" At least that got a smile out of her - that, and my confession that my alternative career choice would have been stand up comedian!
I did survive Trig, though I am of absolutely no help with it now. She has a fancy scientific calculator, and I remember endless formulas done by hand. I have a vivid memory of sitting in the class one day, feeling miserably sick to my stomach but refusing to leave because I did not want to miss the class and get behind. Thankfully I passed, but sadly my life as a mother and homework monitor has pushed any residual knowledge of higher math to the inaccessible regions of my brain. My life as a quilter, though, has definitely sharpened my understanding of basic geometry!

In fact my ability with math has greatly enhanced my quilting, giving me the ability to draft blocks in any size I desire, and even makes shopping for fabric an easier task as I can estimate the amount of yardage needed for a backing or a border. I find that the reason why a lot of people stick to basic patterns is that they don't like doing the math and find that it's easier to simply follow a list than it is to create something of their own, so I am glad that my math skills have helped me create my own unique quilts!

If you are working with triangles, you definitely need to have a handle on your fractions because a half-square triangle of any certain size needs to be cut 7/8 of an inch larger for the seam allowances. And good old Pythagoras? His theorem tells us how to figure the diagonal line of the square, very useful for setting blocks on point and figuring the size of those setting triangles we'll be needing.

In order to figure yardage you are definitely going to have to do some multiplying and dividing, then you'll probably have to convert your numbers into actual yardage so knowing how to do that is important - here is a handy Cheat Sheet for converting fractions into decimals and inches into yards or decimals. I can usually do it in my head (due to working in a quilt shop!) but sometimes it's nice to have an easy print out to refer to so you can save your brain for deciding on color schemes!

In fact, quilters use math so much we even have a special calculator made just for us! The Quilter's Fabric-calc is available in many quilt shops and is a handy tool to help make the math a little easier! I'm all about tools, but this is one that hasn't found it's way into my arsenal yet. It does look interesting, though!

Now, not every quilter needs to have passed Trigonometry, but it really does help to have a grasp on your basic math skills. I just look on quilting as one more way to keep my brain active, which is a very good thing. Now I just wish there was a way I could make quilting a more aerobic activity so I wouldn't have to figure out a way to keep my body as active as my brain is. I suppose I'll have to stick with daydreaming about quilts when I do my daily miles!
Happy Quilting!


Pam Geisel - For Quilts Sake said...

Fun column! I've said that math isn't my strong suit and my DH replied that math wasn't a suit it my deck! But I've learned a few things:

I can now add and subtract fractions because I picture a ruler...wish someone had taught me that in school.

The Pythagorean theorem is the only thing I remember from math class, and I've used it to figure out quilt desings, only I keep getting a lot of 1/3 and 1/6, which aren't on my ruler.

My best math advice is: if you change the size of the squares or any other element halfway through making the quilt, be sure to stop and refigure the amount of fabric you need for the borders and backing!

connie said...

I love your post. I have a bit of advice you can pass along to your daughter, my son had a professor who he did not understand so he went on line and found you tube videos on the subject and found someone who explained the concept in a way it made sense. So in his world if you need help with anything there is a you tube video on the subject. :-)