Each starting Shapedoku grid includes some numbers that are already placed (see fig. 4). These numbers are circled so that they can be easily distinguished from other numbers as they are placed in the grid. In addition to these starting numbers, solvers are provided with a list of shapes that are created by connecting the centers of the squares containing the noncircled numbers in the solution. Note that the starting circled numbers are not used in forming the indicated shapes. Thus, in a 5×5 Shapedoku puzzle, for example, a type of quadrilateral is created when there is one specific circled number, and a type of triangle is created when there are two specific circled numbers. For example, in the puzzle shown in figure 4, the two circled 4s imply that the missing 4s lie in the shape of a triangle.