Try using plot3() to plot the data. Perhaps visualizing it is the first step to solving it.
% A(0,0,0), B(1,0,0) A'(0,0,3), B'(1,0,3) C(1,2,0), D(0,2,0) C'(1,2,3), D'(0,2,3)
data = [0,0,0; 1,0,0; 0,0,3; 1,0,3; 1,2,0; 0,2,0; 1,2,3; 0,2,3]'
x = data(1,:);
y = data(2,:);
z = data(3,:);
plot3(x, y, z, 'b.', 'MarkerSize', 40);
grid on;
xlabel('x');
ylabel('y');
zlabel('z');
Another hint: use max() and min() to get the range of the x, y, and z data and use the fact that you know the shape to be a perfectly rectangular block.
After that, read these:
