This works for me with both fill and patch in R2017b:
x = [120 158 165 188 198 145];
y = [ 55 51 89 51 14 14];
figure(1)
fill(x, y, [0.1 0.5 0.9])
axis([100 200 0 150])
axis equal
figure(2)
patch(x, y, [0.1 0.5 0.9])
axis([100 200 0 150])
axis equal
The patch function usually closes the curve on its own. If it doesn’t, close it yourself:
patch([x x(1)], [y y(1)], [0.1 0.5 0.9])
