#Dimensions

Key D — a linear dimension. The angular and the radius/diameter ones are next to it on the panel.

• Linear: clicking a line gives its length, or pick two points. While placing it the cursor chooses the orientation — aligned, horizontal or vertical.
• Angular: two lines (the angle between them) or three points (A — vertex — C).
• Radius/diameter: click a circle or an arc.

#A dimension is a constraint, not a label

A dimension holds the geometry: change the number and the shape changes. That is why dimensions remove degrees of freedom, and why they are not added just to look nice.

#A formula instead of a number

A dimension field takes an expression: 40/2, w*2, len+5, sin(30)*10. Names come from the global parameters (“ƒx Parameters” in the top bar). This is how dimensions that must change together are tied.

#Driven dimensions

If a new dimension would be redundant (the same thing is already set by other constraints), the program makes it driven: it shows the measured value but holds nothing.

But if the dimension conflicts with the existing ones, it will not be made driven: the conflict is flagged so you can see it and decide which dimension is the odd one out.

#See also

• Parameters and formulas — how to name a dimension and use it across the part.