Is it possible to draw dimension of the angle in Sketchup 8?
I use a plugin called "angular dimension"
Not sure if it works in 8 though.
There is a new version Angular Dimension 2 (v6.0), you can find it here (free login required):
Read the ‘More Info’ Documentation about Angular Dimension 2 on the SketchUcation Plugin Store. It works in v 8, but if you move the mouse ‘too much’ while using the tool it can cause a Stack Overflow, and crash SU8.
Note: my older, less sophisticated angular dimension plugin is still available from the sketchucation store. Because it was originally written back then it runs fine on SU 8.