Hi, friend! It seems you are studying the finite element method.
For fem analysis, two important things for preprocessing are nodes and elements.
Usually nodes are stored in a n-by-d matrix (n is the number of nodes, d is the dimension), for example
nodes = [0,0,0; 1,0,0; 1,1,0; 0,1,0; 0,2,1; 1,2,1];
elements are stored in a m-by-s matrix, in a quad element with 4 nodes, s=4, and m is the number of elements. Elements record the node identity and their arrangement in an element. Here two elements are
elements = [1,2,3,4; 3,4,5,6];
IF YOU want show the two shell elements, then use patch function
patch('vertices', nodes, 'faces', elements, 'facevertexcdata', nodes(:,3),'facecolor','interp')
IF you want get the nodes of the second elements, just do
ecoor = nodes(element(2,:),:)
Here 2 represents the second element.