The Rolling Ruler is a universal drawing tool for making parallel lines, circles and arcs.
Draw Horizontal Parallel Lines Hold the centre of the ruler and roll it up/down to draw the straight parallel lines.
Draw Circle and Arcs Place the pencil in any hole to act as a pivot. Place another pencil in any hole and swing the ruler to produce an arc or circle. Circle of up to 60cm diametre can be drawn this way.
Draw Angles First draw a horizontal line. Then place the ruler against the line using the protractor guide to get any desired angle