By Laura Loewen

Our first month’s skill is Half-Rectangle Triangles (HRT). These differ from Half-Square Triangles (HST) because they are directional, which means the direction you sew your diagonal makes a difference in the finished unit appearance. Another difference is that you do have to do a very tiny amount of math to figure out how big to cut your starting fabric rectangles. However, the biggest departure from HST construction is that the quickest and simplest HRT method uses a template.

We will teach you how to draw your templates and figure your cutting math so that you can apply this to almost any size HRT you want to make. The block features 3 sizes of HRTs so you will have plenty of practice building your skill.

Half-Rectangle Triangle Supplies

Template paper, trace paper, or printer paper
paper scissors
pencil/pen
ruler

Step 1 – Make HRT Template

Draw a rectangle the size you want your *finished* unit to be. (Finished does not include seam allowances). Make sure to draw this rectangle at least ¼” from the edge of your template paper.

Draw a diagonal line from corner to opposite corner, extending beyond the edges. (For regular printer paper, draw 2 diagonal lines. For trace or template paper, draw one diagonal line; the template can be flipped to be reversed).

Draw the seam allowances ¼” outside the original finished rectangle. Note that the diagonal lines meet the corners of the finished rectangle exactly, they do not meet the corners of the larger, seam allowance rectangle.

Cut out the template on the seam allowance lines.

Step 2

Figure starting rectangle size and cut 2 from contrasting fabrics.

Always add 1.5” to the short side. Figure the rectangle ratio and add up to 2” to the long side. Figure the ratio by dividing the larger number by the smaller number. The ratio is 1:[answer from division].

Examples: 

For a finished 4”x6” HRT, cut starting rectangles at 5.5”x7.5”. Because the ratio of the rectangle is 1:1.5, only add 1.5” to the long side.

For a finished 4”x8” HRT, cut starting rectangles at 5.5”x10”. Because the ratio of the rectangle is 1:2, add 2” to the long side.

For a finished 2”x6” HRT, cut starting rectangles at 3.5”x8”. Because the ratio of the rectangle is 1:3, greater than 1:2, add just 2” to the long side.

Step 3

Place rectangle pairs right sides together. Draw a diagonal line on the back side of the top fabric in the opposite direction the HRT will be oriented.

Step 4

Rotate the top rectangle ¼ turn and match corners. Check orientation by holding in place and flipping back a free corner.

Step 5

Stitch ¼” on either side of the drawn line.

Step 6

Cut on line and press open. You will have 2 identical HRTs.

Step 7

Align the template diagonal line with the diagonal seam. Trim excess fabric from around edges of template.

Rebecca Greco
Author: Rebecca Greco