How to measure the continuous segments (polyline)?

1. When you encounter a straight line, left click on both ends of it. While encounter an arc, left click on the arc itself.
2. Right click to finish the measurement, and left click to place the measurement.

Attention: An arc could be automatically recognized when the mouse turns into a small white square. If the mouse turns into a small yellow square, it means it’s not an arc but a polyline which consists of multiple line segments, and you need to select them one by one for measurement.