SYMmetryplus74

Number 74 Spring 2021 MRS BROWN’S QUILT The Tethered Goat Problem The Tethered Goat Problem has been in the mathematical news recently. This problem stems from one posed in the 1748 issue of The Ladies Diary: Or the Woman’s Almanack . Here is the original problem and the start of its solution (the rest of the solution can be found in the answers on the MA website). The original solution by Mr Heath is an approximation. As time passed, the horse became a goat and rather than the area to be grazed being outside the circle, the inside was considered. Interest grew and the circle became a sphere and the tethered horse turned into a tethered bird, with area replaced by volume. Late last year, Ingo Ullisch, a German mathematician found an exact solution using a branch of mathematics called complex analysis. An excellent description of the story can be found by searching ‘Quanta goat problem’. Recent News During lockdown Julia Brown completed this quilt. She pieced it together about 40 years ago and never got round to finishing due to a family and full-time teaching. It is about 6 feet by 6 feet (about 180 centimetres square). The article in SYMmetry plus 72 (Mrs Perkins’ Quilt), reminded her about the project. All the designs are traditional American ones and whilst some are applied to the base fabric you will see most are made from various geometric shapes pieced together. So, while looking at the quilt, why not think about the symmetries of each design (reflections and rotations) and the names of the polygons used. It is well worth reading about books and articles on the geometry of quilts on the internet.