Place the pointed end of the compass on a point on the map.
Place the pencil end of the compass on another point of the map and move the compass circularly to form a circle on the map.
Measure with a rule the distance from the center of the circle to an outside point of the circle. For example, three inches.
Convert the measurement in Step 3 to the proper scale. In example, if the map says one inch equals five miles, then the radius on the map equals fifteen miles.
