[Graphs generated by this script: initPicture(-3,13,-3,25);fill='yellow';path([[0,0],[0,13],[5,22],[10,13],[10,0],[0,0]]);text([0,6.5],'13','left');text([5,0],'10','below');text([5,15.25],'9','right');stroke='gray';line([0,13],[10,13]);line([5,13],[5,22]);]

Find the area of the shaded region above.