Block 3a is the basis for an Ocean Waves quilt, 54/40 or Fight, Tennessee Waves and any number of quilts using straight lines to create the illusion of curves. The triangle units in the side squares were christened Peaky and Spike by the late Doreen Speckman, Peaky being the larger mountain shaped isosceles triangle and Spike (like a tent peg) the two half versions of this needed to complete the square. I haven't worked out how to rotary cut this unit using normal straight rulers though no doubt it's possible so templates are a natural if not the only way to go.
Whichever method is used you have to remember that the Spike units are REVERSED so you have to turn your your template over or cut two units at once with fabrics reversed, right or wrong sides together.
When cutting the Peaky units the short side is on the straight grain and care needs to be taken with the slightly bias longer sides.
A mathematical friend told me isosceles is Greek for long legged.
The squares are rotary cut from 4.5 inch strips.
|Peaky & Spike units|
|Spike units need to be cut "reversed" like these pairs which|
will frame two Peaky's
|Units laid out ready for assembly|
|Units sewn into rows ready|