The Angle measurement tool places specialized markups that calculate an angle.
As with any measurement, be sure to calibrate the document first.
This function is only available for Studio Session PDFs.
Taking an Angle Measurement
Angle on the 
Measurements tab. Tips:
Resizing or Adjusting an Angle Measurement
Select a markup to reveal its control handles. Each handle controls a different aspect of the markup's size and orientation.
To rotate the markup, click and drag the orange handle outside the markup (when the markup is first placed, it will be at the top). By default, the markup is rotated in increments of 15°; to rotate in increments of 1°, hold down SHIFT while dragging.
The rotation can also be entered in the Rotation field found in the Layout section of the Properties tab.
To rotate the caption, click and drag the orange handle directly over it. By default, the markup is rotated in increments of 15°; to rotate in increments of 1°, hold down SHIFT while dragging.To return a rotated caption to its original position, right-click it and select Reset Caption Position.
To move the entire markup together, click and drag a part of it other than the control handles.
To resize a line or change its angle, click and drag the appropriate yellow handle.
To scale the markup up or down, click and drag the appropriate purple handle.
Changing an Angle Measurement's Appearance
The appearance of the Angle measurement is configurable, including line color, style, width, and opacity, as well as the font style of the caption and whether or not to show it.
To change the appearance of an Angle measurement, select it and click the 
Properties tab.
Tabs > Properties or press ALT+P to show the Properties tab if it is hidden.
Appearance Properties
Color: Sets the line color.
Fill Color: Controls the fill color of the endpoints.
Highlight: Makes the fill color and line transparent so underlying content shows through.
Opacity: Sets opacity level of the line and endpoints, from 0 (invisible) to 100 (opaque).
Line Width: Sets the line thickness in points.
Style: Determines the pattern of the line segment.
Start and End: Controls the appearance of the endpoints for each side of the line. The diagram below shows samples of each type of endpoint.
Each endpoint has an associated Scale that determines the size of the endpoint in relation to the Line Width. By default, it is set to Auto and will automatically adjust as the Line Width is changed.
Show Caption: Select to include caption text on the markup. Click Edit to choose which measurements to include.
Font: Sets the font used for the selected text. Available fonts are divided into three regions:
Note: If you attempt to embed a font for which the viewing and editing permissions do not allow formatting, Vu will display a message indicating the font will not be embedded in the PDF.
Font parameters are retained in the PDF such that even if the original font is not embedded or on the viewer's workstation, a suitable representation of the font will be substituted.
Font Size: Sets the size of the font.
Text Color: Sets the color of text.
Font Style: These settings control the formatting of the text. Options include Bold, Italic, Underline, and Strikethrough. Generally, any combination of these styles can be applied to format the text.