There’s a lot of math involved with sewing.  Fractions are very important, such as when using seam allowance, but did you know that geometry is also involved?  To use this part of math we are going to make a water bottle holder.

You will need:

1. five colors of  fabric fat quarters or other quarter yard pieces

2. two pieces of white paper

3. a compass , ruler, and pencil

4. scissors

5. thread and needle as well as a sewing


How to make

1.)    Cut out a rectangle that is 6 x 12 from the contrast fabric.


2.)    From the contrast fabric cut out a circle that is 4 ½ inches in diameter.

3.)    Repeat step 3 with one of the patchwork colors.

4.)    Create a pattern for a perfect square that is 5 inches using a ruler and a compass.

5.)    Cut 10 -12 squares cut one – three squares out of each of five or six different fabrics.(For less variation you can use fewer fabrics.

6.)    Cut each square in half diagonally creating congruent triangles. Because the triangles are congruent, they can match up in any order and still form perfect squares. You can then adjust the seam allowances to make them bigger or smaller so that the squares won’t appear congruent. Match two triangles together when sewing the squares together and it will look like a bigger triangle with its base bisected forming two right triangles. You can use the angle side theorem to prove that these triangles are also congruent.

7.)    Lay out the triangles mixing and matching triangles to create new squares pin and sew along the diagonal.


8.)    Pin and sew the squares right sides together in rows of 8.

9.)    Sew the two rows together to form a rectangle. Cut this piece of fabric to form a 6 x 12 inch fabric.

10.) Pin right sides together and sew along the 6 inch side seam.

11.) Repeat with the other rectangle.


12.) Now pin the contrast circle to the bottom of the contrast rectangle.

13.) Repeat with the patchwork rectangle and circle.

14.) Notch the seam at each of the circles.

15.) Turn one of the pieces right side out and leave the other wrong side out.


16.) Pin right sides together.

17.) Cut a piece of strap 24 inches long.

18.) Put most of the strap in the area where the right sides are together.

19.) Pin one end to the edge of the matching pieces of the water bottle holder, making sure that the strap is between the two pieces. (Unpin a little spot if necessary.)

20.) Sew around the matched edges leaving a one inch opening (or bigger if the strap is wider.

21.) Cut hanging threads and turn right side out.

22.) Thread the loose edge of the strap through the opening and sew.

23.) Use and enjoy.

Note: Human error in cutting and sewing can lead to your triangles and squares not being congruent.