Markup Angle measures angles within an image, and reports the measurements directly on the image.
To measure an angle
Navigate to the image you want to measure.
Use the appropriate Zoom or Magnification tools to zoom in on an area of the image.
Click on Markup Angle.
Click on the image to set the first point of a line.
Move the cursor to the end of the object you are measuring.
Click to set the second point. The angle of the line is shown in degrees.