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    How to tell half square triangles apart from quarter square triangles

    Both HSTs and QSTs are identical in shape. Each have two equal short sides that form a 90 º angle which is opposite to a longer third side. So what makes them different when used in quilts?.

    Understanding which way the grain line of the fabric runs
    in triangles makes it easy to tell them apart. Here's why:

    This method works for many blocks except for the blocks like these that contain patches with three triangles making one square:

    We all know that in quilting you never want a bias edge that can stretch out of shape on the outside of a block or unit. We always start by first squaring up our fabric, so that we cut our strips on the straight grain.

    When we make triangles with a quilt ruler,
    we start by cutting strips and squares.

    The grain line on the suares runs straight
    up and down and side to side.

    Knowing this makes it so much easier to
    tell Half & Quarter Square Triangles apart.

    When you look at each individual patch with triangles in it, if the short sides of the triangle are on the outside, it is a Half Square Triangles. And if the long side is on the outside, it is a Quarter Square Triangles.

    Look at each individual patch.


    Both HSTs and QSTs are identical in shape. Both have two equal sides that are shorter than the one long side.

    It's hard to tell them apart in the blocks like these:

    Scroll down to watch the video that shows you how.

    As shown in the video, understanding which way the grain line of the fabric runs in triangles makes it easy to tell them apart. Here's why:

    This method works for many blocks except for the blocks like these that contain patches with three triangles making one square:

    It gets even tougher to tell them apart in blocks and units like these:

    We all know that in quilting you never want a bias edge that can stretch out of shape on the outside of a block or unit. We always start by first squaring up our fabric, so that we cut our strips on the straight grain.

    When we make triangles with a quilt ruler, we start by cutting strips and squares.

    The grain line on the suares runs straight up and down and side to side.

    Knowing this makes it so much easier to tell HSTs & QSTs apart.

    When you look at each individual patch with triangles in it, if the short sides of the triangle are on the outside, it is a Half Square Triangles. And if the long side is on the outside, it is a Quarter Square Triangles.

    Look at each individual patch.

    Short sides of an HST and long side of a QST are on the outside: