In the triangular pyramid s-abc, if SA is vertical to BC, SA = BC = a, SA is vertical to de, BC is vertical to de, and de = B, the volume of the triangular pyramid s-abc is obtained

In the triangular pyramid s-abc, if SA is vertical to BC, SA = BC = a, SA is vertical to de, BC is vertical to de, and de = B, the volume of the triangular pyramid s-abc is obtained

Connect AD and SD because SA ⊥ BCDE ⊥ SCDE ∩ SA = e, so SC ⊥ face sad because SA ⊥ De, so V (s-abc) = s △ sad * BD + s △ sad * DC & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp