Eleven matchsticks are arranged into a big “mountain” shape. Using three additional matchsticks it is possible to divide the shape into two parts of the same area.
Will the dividing line touch any of the shape’s corners?
The line starting at one of the triangle’s bottom corners and ending exactly in the middle of its opposite side divides the triangle in two halves of the same area. The three matchsticks put together have slightly bigger length than that line. Then the “zig-zag” principle is used to place those three matchsticks along the dividing line – as is shown in the diagram. The dividing line touches one of the bottom corners.