When the length is too short, the bookcase will seem concave, and when he is too long it will seem convex. Dice that the quadrature of a project is the measurement of its stability, squaring must be a squared, and not rhombus. In order to verify the quadrature of the project, it measures the two diagonals with a meter. It imagines that the squared one is made up of two stuck triangles. The hypotenuse of the triangles is the diagonal of the squared one. Then, to be able to measure the diagonals of the squared one, it places an end of the meter in one of the inner corners of the squared one. The length obtained when measuring from that corner to the opposite corner is the length of the diagonal. The length of the other diagonal can be measured following the same procedure.

After to measure the length of the diagonals, it must verify that both S-values equal. If they are not equal, must push with force until obtaining that these S-values equal. When the pressure of the screws does not allow that its force manages to square the wood, afljelos a little and tries again. An alternative to this is to use the pressure exerted by the screws to square the project. Instead of to orient the screws of parallel way to the materials that are being beaten, orintelos with small angle with respect to these materials. With a small deviation in the angles, it can exert the pressure necessary to logar the quadrature. For example, if it wishes to extend a short diagonal, the head of the screw must be oriented so that she is remote of the other parts, to manage to produce squared when applying a pressure. Assembled in dry the test versions they are important because they serve to polish the end item. That is what means the assembled one in dry exactly.