statics: matrix solution for tripod axial members

Use this formula:
$\text{MatR} = \left[ (\text{MatA})^T \times (\text{MatB})^{-1} \right]^{-1} \times \text{MatC}$

Where,
MatR = Reaction Matrix of tripod members
MatA = Direction Matrix of tripod members
MatB = Length Matrix (diagonal matrix) of tripod members
MatC = Negative of the Load Matrix