SS1 = [2.5, 0, 0] - [3.5, -3, 3.5] = [-1, 3, -3.5]
SS2 = [0, -5, 0] - [3.5, -3, 3.5] = [-3.5, -2, -3.5]
SS3 = [0, 0, 2.5] - [3.5, -3, 3.5] = [-3.5, 3, -1]
[3.5, -3, 3.5] + a·[-1, 3, -3.5] + b·[-3.5, -2, -3.5] + c·[-3.5, 3, -1] = [0, 0, 0] --> a = 7/12 ∧ b = 3/12 ∧ c = 7/12
Damit liegt der Ursprung nicht in der Pyramide.