To Set Units
1. Click > 
Units. The Units Manager dialog box opens on the Systems of Units tab. A blue arrow points to the current unit of measure.
Units. The Units Manager dialog box opens on the Systems of Units tab. A blue arrow points to the current unit of measure.2. Select a different unit of measure.
3. Click Set. The layout converts to the new unit of measure. If the units have changed, and must be scaled, the Changing Model Units dialog box opens.
4. Click Convert dimensions (for example, 1” becomes 25.4mm) to scale the dimension values and retain the size of the model, or click Interpret dimensions (for example, 1” becomes 1mm) to keep the dimension values the same, which will change the size of the model (for instance, when you change the unit of measure from inches to centimeters, 1 inch = 1 cm).
 | Angular dimensions are not scaled. A 30º angle, for example, will remain a 30º angle. |