Given the following planar block slide data: Mohr–Coulomb failure criterion applies

1 slope height                          H = 613 ft (187.8 m);

2 failure surface angle           α = 34^◦;

3 slope angle                           β =?^◦;

4 friction angle                        φ = 30^◦;

5 cohesion                               c = 1440 psf (0.069 MPa);

6 specific weight                     γ = 162pcf (26.63kN/m³).

Find the maximum slope angle β possible, when the water table is drawn down below the toe of the slope. Note: No tension crack forms.