It's about 10 inches (25 cm) along the center back. I love the embossed texture and gracefully scalloped lower edge; the faggoting bands need blocking for best effect.
Other participants of the KAL have noted the bland names of the designs; to me, A Handsome Triangle reeks of scandalous assignations and colonial oppression. In that Victorian laissez-faire spirit I blithely substituted yarns and modified the pattern. The yarn is Rowan Rowanspun DK, colorway 747 Catkin. Despite its crunchy look, it's actually very soft (a tad too soft for my druthers). The pattern calls for 950 yards (868 m) of laceweight; I have three skeins or 657 yards (600 m) of Rowanspun or about 69% of the pattern yardage. Uh-oh. Having a modern sense of anxiety, I started worrying about Not Enough Yarn.
When in doubt, I knit gauge swatches. The stitch pattern is fun to work and easily memorized, yet it's true lace knitting, with pattern rows on both the right and wrong sides of the fabric. To enhance the yarn's tweedy texture, I worked paired right- and left-leaning decreases rather than go with all right-leaning decreases as given in the pattern. In very fine yarn, the slant of decreases often is hardly noticeable, but it's more obvious in heavier weight yarns. Plus I'm fussy about such things and disliked the look of the swatch (the bottom half is worked as per pattern, the top half the way I prefer) – for that matter, the close-up in the book drives me nuts. I also worked the center panel of the shawl in garter stitch rather than stockinette stitch – I think it's attractive in its own right and also complements the garter stitch neck edge.
Some quick back-of-the-envelope scratches allayed the concern about Not Enough Yarn. (Gentle reader: if MEGO sets in, just skip to the bottom line.) I figured yardage roughly translates into shawl area. For a triangle shawl,
where the base is the length of the neck edge and the altitude is the length of the center back. Additionally, for a half-square triangle shawl such as Handsome, b = 2a and therefore A = a², in theory, anyway. So... [waves hands over more math involving square roots]... if three skeins are used, the center back length when the first skein is finished is about 57% of the completed length before blocking. Put another way, the center back length of the unblocked completed shawl should be about 1.7 times the center back length of the WIP when the first skein is finished.
Non math geeks still reading may be wondering why I didn't just estimate that I have 69% of the yardage called for in the pattern, so my shawl should have 69% of the linear dimensions of the pattern. Well, that would be OK for a shawl that has a more or less constant row stitch count, but this shawl is worked from the center neck outwards and the row stitch count increases at a constant number of stitches but a decreasing rate. (Unlike a pi shawl, which increases at an increasing number of stitches but a constant rate.) Attentive readers will have noticed I'm finessing the effect of the heavier weight yarn, because yarn weight is usually secondary to yardage when worrying about Not Enough Yarn.
Bottom line, my Handsome should be a reasonable-sized shawl. [g]