You can dimension the true length of the arc.
The default dimension type for an arc is radius. You only need to select the arc for this dimension type.
To dimension the true length of an arc:
- In an open sketch, click Smart Dimension
(Dimensions/Relations toolbar) or .
- Click the arc.
- Click the two endpoints of the arc.
- Move the pointer to show the dimension preview.
- Set the value in the Modify box and click
.
- Click to place the dimension.
Video: Dimensioning Arc Length