In this video, they discuss the triangle quilt block which is a triangle shape instead of the typical square shaped block. This block is also know as the Smoothing Iron with angles that are made up of 60 degrees.
The reason it is called the Smoothing Iron quilt is because it relates to the iron they used in the past. The pointed shape of the iron is similar to the pointed shape of the triangle. On the design table, Fons & Porter show how to make the smoothing Iron quilt blocks from cutting the patchwork to piecing the blocks together with triangles.
(SMQ magazine, November ’96)
Smoothing Iron Quilt – Episode 404