For the hyperstatic lattice structure in Figure $5,$ determine the force in the frames $1-2,2-3$ and $2-4$ using the matrix method.

We give:

E $=200$ GPa

Section areas:

$12=300$ mm$2$

$23=200$ mm$2$

Consider the following directions for the members: $2=>1$; $2=>3$; $2=>4$

Figure $5$