Calculate displacement from velocity-time graph

3) A velocity-time graph is provided. Find the displacement $S$ represented by the area under the curve.

This question includes visual content: A hand-drawn velocity-time graph on grid paper. The vertical axis is labeled $v_x$ and the horizontal axis is labeled $t$. A line starts at $v_x = 6$ on the vertical axis and slopes downward to a point where $t = 5$ on the horizontal axis. The region under this line is enclosed by the axes and vertical lines at $t=0$ and $t=5$, forming a trapezoid. The text '3)' precedes the graph, and 'S =' is written to the right.