Lightly sketch a horizon line across the middle of the page. Start the outline of the barn with a rectangle for the long side, then add the front as a rectangle that is open at the top. All the vertical lines should be parallel. Connect two of the vertical lines with two angled lines, as shown.
Use slanted rectangles for the roof. Begin the edge of the lake with a nearly straight line to show the edge of the water. Draw another, irregular line above it to show the limit of the sandy area.