 A radius dimension allows 
 the user to display the radius for any arc or arc-shaped pattern. The 
 system calculates the radius from the center of the pattern. Select any 
 of the snap points and then rotate the dimension text and line around 
 the arc.
 A radius dimension allows 
 the user to display the radius for any arc or arc-shaped pattern. The 
 system calculates the radius from the center of the pattern. Select any 
 of the snap points and then rotate the dimension text and line around 
 the arc.
Notes: The Radius command affects any pattern consisting of arcs, including pattern arcs and pattern circles.
Usually the radius dimensioning extends from the center of the arc to the outer edge. However, if the arc is too small, the dimensioning line appears pointing to the outside of the arc.

 A diameter dimension allows 
 the user to display the diameter for any arc or arc-shaped pattern. The 
 system calculates the dimension from the center of the pattern. Select 
 any of the snap points and then rotate the dimension text and line around 
 the arc.
 A diameter dimension allows 
 the user to display the diameter for any arc or arc-shaped pattern. The 
 system calculates the dimension from the center of the pattern. Select 
 any of the snap points and then rotate the dimension text and line around 
 the arc.
Notes: The Diameter option affects any pattern consisting of arcs, including pattern arcs and pattern circles.
Usually the dimensioning line extends from the center of the pattern to the outer edge. However, if the pattern is too small, the dimensioning line appears pointing to the outside of the arc.
