A1={[1, 1; 1, 5; 3, 9; 4, 2; 4, 6; 6, 2; 7, 6; 6, 9; 9, 9]};
A = cell2mat(A1);
figure
plot(A(:,1),A(:,2),'oc','LineWidth',2,'MarkerSize',5);
axis([0 10 0 10]);
xlabel('X-Coordinates')
ylabel('Y-Coordinates')
grid on
hold on
for ii = 1:size(A, 1) - 1
    for jj = ii + 1:size(A, 1)
        line([A(ii, 1), A(jj, 1)], [A(ii, 2), A(jj, 2)])
    end
end