These equations for the Mohr circles show that all admissible stress points ( σ σ n , τ τ n ) lie on these circles or within the shaded area enclosed by them (see Figure 10). Stress points ( σ σ n , τ τ n ) satisfying the equation for circle C 1 lie on, or outside circle C 1 . Stress points ( σ σ n , τ τ n ) satisfying the equation for circle C 2 lie on, or inside circle C 2 . And finally, stress points ( σ σ n , τ τ n ) satisfying the equation for circle C 3 lie on, or outside circle C 3 .