Measuring Angles
To measure the angle between two lines:
1. Click Tools, Measure and Angle.
2. Click a point on the first line.
3. Click a point on the second line.
Similarly, to measure an arc segment angle, click the arc start and end points.
The angle between two tangents drawn at an intersection point of two circles can be measured by clicking a point on the first circle and then a point on the second circle.