Delectable Mountains Block - I still suck at math

My Dandelion Quilt posts so far:
Design
Sky and Wishies
Pieced Dandelions
Delectable Mountains Block
Bear Paw
Barrister's Block

In Which the Author Fails at Math

It's hard to blog coherently about confusion, and even basic math is a fog of confusion for me.  I am not one of those who proudly declares she's "terrible at math" because said deficiency is socially approved (much as not being a "morning person", not liking Mondays, and not being able to resist office snacks are foibles socially approved).  My lack of math skills is frustrating and awkward; sometimes I really wonder if my brain is just built wonky, because I can't hold numbers in my head for even a minute.  When I'm at the gym, lifting weights, I'll have to count and add all the plates on my bar multiple times EVERY TIME I ADD MORE WEIGHT!  I'll be like "35 lb bar, plus ten on each side is... 35, 45, 55.  Plus two fives, so that's plus ten... wait, what was I adding ten to?!"  Every damn time.  The coach is like "Great job, Karen?  How heavy was that?" and I forget instantly, even if I just figured it out.  The more numbers there are, the more I feel like I'm in a sea of strange faces, blank and indistinguishable, and not one is a friend. 

So when doing quilt math (as I did last time), I do and re-do all my figures, check them against my ruler, and hope I wrapped my head around things right before I cut.  If some other source tells me different than what I figured, I trust the other source more, because I have no faith in my own figures.

So, let's look at the Delectable Mountains block.  Here's what it's supposed to look like:

Pretty simple, right?  I need to cut and sew large half-square triangles (HSTs), then slice them vertically, then re-order them.  My goal is 12.5" blocks when I'm done, and there are four seams (one diagonal and three vertical), so I need to add quarter inch seam allowances eight times, which means my original squares should be 12.5+(0.25 x 8) = 12.5 + 2 = 14.5 inches.  Since my seams might not be perfect, I round up to 15 inches for safety.  The math is right so far. 

Remember when I wrote "My first instinct is to cut 15" strips along the Width of Fabric (WOF).  If I cut enough for three squares (in medium and dark green), I'll have six HSTs when I only need five.  Is there a better way to cut?"  That question was my first mistake.  I should have just stopped with my first instinct.  Instead, I tried to economize fabric by cutting differently.  Using a tutorial from Blossom Heart Quilts, I muddled through a Pythagorean equation and determined that the key measurement I needed, the x-height, was 10.6". 

And then remember when I wrote "Incidentally, if a 15" square is 15" on its diagonal, and the x-height is the measure from the center to the corner, why wouldn't that just be half of 15"?  Then I pulled out a square ruler and saw the halfway point was 7.5"?  Yeah... a 15" square is not 15" on its diagonal; it's 21.213". 

I should have cut my strips at 10.6" (plus 0.5" for seam allowances).  I don't know why I was so certain that four equal sides meant the diagonal was also equal to the sides.  I don't know why I saw 7.5" on the ruler.  I hate math so much. 

This is a long and frustrated way of saying that I think (still not sure) I should have cut my strips at 11" and then zig-zag cut them to get the HSTs I needed.  That's not what I did.  I cut 8.5" strips, for reasons that made sense at the time.

STRIP PIECING

This picture shows the 8.5" strips (two shades of green) sewn together on both ends.  I'm chalking the zig-zags, to get right-angle triangles on either side of the seams.  Then I cut.  Success!  Sort of.  I do get Half-Square Triangles, just as promised.  But they are too small!  So what to do?  I can't resew what I've cut and then piece it into wider strips, because that'll be a seamy mess.  Nor can I cut new strips because I don't have enough of the Dark Green.  How unbelievably stupid and frustrating. 

The mind adapts and converts to its own purposes the obstacle to our acting.  The impediment to action advances action.  What stands in the way becomes the way.                                                                                                                                     -- Marcus Aurelius, Meditations, Book 5.20

I know I have enough of the Medium Green to cut a new strip, the right width.  The Dark Green is my paucity... What I have to do is make the new wider strip with the dark green I had reserved for the Hawai'ian appliqué , and find some other fabric for the appliqué.  

Here you can see my new, wider strips; the Medium green cut from whole cloth and the Dark Green pieced from smaller bits.  By this point I have given up on Pythagoras and decided to make my HSTs by cutting 15" squares and sewing them diagonally.  So these two strips are cut 15" wide, and then sub-cut to 15" squares. 

grrrr... that seamed mess!

I sew my HSTs similar to how I did the eight-at-a-time method demonstrated here; this time I only mark one diagonal and sew on either side of it.  The raw pieces start at 15" square.  When I cut them apart, I get two HSTs of 14.5" square, which I trim to 14" square.

The next bit is trickier.  I measure inward from the corners, and make vertical cuts at 3.5".  Measuring in from the corners means that I keep the HST running neatly into the corner of those strips.  Then I bisect the center piece and trim those pieces to 3.5" wide, as well.  Now I have four columns, 14" tall by 3.5" wide.  I reverse their order, and there's my Delectable Mountain shape! 

If I sew the columns back together like this, I'll lose 1.5" in seam allowance, and I'll end up with a rectangle: 14" x 12.5".  So I need to trim the columns' height by 1.5" first.  For columns A and D, I trim 1.5" off the side that doesn't have the diagonal seam, because I want to keep that diagonal seam in the corner.  For pieces B and C, I trim 0.75" off both top and bottom, the keep the diagonal seam in the middle.  Now my columns are 12.5" x 3.5".  When I sew them together I'll have a 12.5" square! 

MOUNTAINS OR GRASS?

I now have a design quibble.  The block is meant to be arranged as you have seen, with the mountain peaks ascending/descending evenly.  But I intend this block to be reminiscent of grass, not mountains, and so I'm inclined to make it less of an incline, and more jagged.  I rearrange the columns once more, and finis! 

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With this block and the Barrister's Block done, I am done all my piecing for this quilt top, and ready to do my appliqués!  Hurray!