This is the final instalment of our rotary cutting series and looks at cutting the triangles needed for the Peaky and Spike unit.
The centre triangle is an isoceles triangle – its height and base are the same length, so you can cut it from a square. The triangles at the edges (long, or skinny triangles) are half as wide as their length and are thus cut from rectangles.
The square for the centre triangle should be cut 1 inch larger than the finished unit. If you want to cut more than one triangles then cut a strip 1 inch wider than the finished unit – for a 3 inch unit, cut a 4 inch strip.
Mark 4 inch squares along the length of the strip. Make sure you mark on the wrong side of the fabric as these marks may be visible later. The marks in the photos are heavy and thick so they show up, yours should be much lighter.
Now its time for the skinny triangles. The rectangles should be 1 + 1/4 inches longer than the unit and 5/8 inch wider than half the width of the unit. So our 3 inch finished size units needs rectangles that are 4 + 1/4 inches x 3/2 + 5/8 (i.e. 2 +1/8) inches. For each unit you need two mirror image triangles – this means you need to cut two rectangles to start with. It is easier if you keep the strip folded and cut the rectangles in pairs.
Cut the paired rectangles in half across one diagonal.