Measure Tool Icon Measure Tool Measure Area Measure Distance Clear measurements Measure Area The first click on the map sets the starting point. Each successive single click adds a point to the area polygon. Double clicking on a point adds the last point and measures the complete area. A new single click on the map starts the process of creating a new area to measure. The original tool button automatically changes into a ‘clear measurements' button (see below), which will clear all areas if clicked:   Measure Distance The first click on the map sets the starting point. Each successive single click adds a point to the line. Double-clicking on a point adds the last point. The length of the line is then measured. A new single click on the map starts a line measurement. The original tool button changes into a ‘clear measurements' button and will clear all lines: