how do you dimension an arc length in an idw?
inv 2008
Thanks

You can use a computed parameter. Create and name the Radius and ArcAngle parameters. Create a new parameter ArcLen and assign an expression to it:
Radius * ArcAngle * PI / 180 deg
Then use the new ArcLen parameter in a dimension.

i guess i have a easier way.
 
when you are in the part file  or in a drawing file
 
go to TOOLS - APPLICATION OPTIONS - DRAWING TAB
 
DRWING TAB HAS GOT "DRAWING TYPE PREFERENCES"
 
SELECT THE RADIUS DOWN ARROW, YOU WILL GET A OPTION OF
ARC LENGTH, CHORD LENGTH AND DIAMTER
 
SELECT ARC LENGTH
 
HIT APPLY AND CLOSE
 
YOU TRY YO DIMENSIN THE ARC, YOU WILL GET ARC LENGTH AND NOT RADIUS.

Yes, this way is easier if you want all your arc dimensions as lengths. See also the Tip 5711 (related tips).