Subplot legend change width and height

How do I change the width and height of my subplot legend ? I manually changed its position in the figure below.

l = legend('Orientation', 'Horizontal', 'RNN (Ours)','AGG (Ours)', 'SLIC', 'SEEDS', 'LSC');
set(l,'Position', [0.4 0 0.5 0.2], 'Units', 'normalized');

The last 2 values of 'Position' do not work. It just changes the position of the legend. Its width and height remain the same. I need to do it using code not gui.