Use the Quick Shapes Tool to draw a 6-sided polygon. On the Infobar, set the number of sides to 6, select the Polygon icon, select Size and Rotation from the drop down list and change the size to 3.5 inches and the rotation to 330 degrees. We want the left and right sides of the hexagon to be parallel to the sides of the page.

Click the magnet icon (on the Infobar) to enable Snap to Objects. Select the Pen Tool and snap a line on the left side of the hexagon. Deselect the line, and use the Pen Tool to snap the center line. Deselect again, and draw the third line on the right side.

TIP: If you don't deselect the line, the new line will be added to the first line. A quick way to deselect is to press the Esc key. This deselects the object but does not deselect the current tool.