The pair of values (σα, τα), which are to be calculated according to equations (2) and (3) for all possible angles α, can be plotted in a σ,τ-diagram (normal stress, shear stress - diagram); see Figure 2 on the right. If one joins all plotted pairs of values, a circle emerges; i.e., all calculated pairs of values form a circle in the σ,τ-diagram.