The button will add a point to the map, indicating the center of your radius. Additionally, it displays the distance in miles or kilometers. You can move the point around the map to adjust the ...

You can do it the old-fashioned way, calculating distances on a paper map using scale of miles and a ruler. But now there are free online map radius tools ... you well under $100.

The Oil and Gas Threat Map; the yellow represents the half-mile “threat radius.” Screenshot: Oil & Gas Threat Map More than 17 million Americans, including nearly 4 million children ...