Finding angles between planes

In versions 3.3.7.0 and later, the function Show angles between planes is available from the Right Click > Plane submenu!

To find angles between folders manually:

To calculate an angle between 2 elements, a view that is perpendicular to both planes must be used. For example, to see the angle between 2 walls, a top-view (horizontal) view allows those 2 walls to be seen from the top. Between a horizontal plane and and a vertical plane, a transecting vertical plane can be used to visualize and measure the angle.

Generally, a transecting free plane is the most efficient way to visualize the angle between folders if one or both of those are free planes.

To find the angle between any 2 planes:

1. Select one of the 2D folders. Find the intersection line between this folder and the 2nd folder with which the angle will be measured. Hint: See Extend Line to Plane for more info.
   

2. Draw a line perpendicular to this intersection. The position isn’t important: simply start with ‘Multiple Lines’ and use ‘Snap Perpendicular’.
   

3. Now, draw an element extending away perpendicularly from the current plane. Start on plane (click 1st point), then use ‘Coordinates’ from the contextual menu to draw the 2nd point relative to the first point. (Can also enter coordinates in the command window – @0,0,20, for example).
   

4. Switch to parent 3D folder, click the checkbox for visibility. Create a new angle finder Free Plane folder by clicking on 3 points on the lines just drawn.
   

5. With the new Free Plane active, off visibility to the parent folder, and turn on visibility to the 2 folders with the checkbox. If the view is correctly transecting, they will appear as lines on the page (view directly perpendicular to both planes). The 3rd line that is extending past is the line drawn earlier to set the plane.
   

6. With 2D Snap active, trace over these elements. After tracing, turn off visibility. Now, the angle between the 2 faces can be ‘seen’ and calculated.
   

*Reminder when calculating mitre angles for cutting: Most saws and CNC’s treat a straight 90deg cut on materials as 0deg. So, mitres should be measured off of this straight cut.