# Constraints Definition Tool

There are many constraints that are available to use on your sketch, each with different functions.
Constraints are imposed onto sketches to ensure that the profile does not change when one of its dimensions is altered.

Distance – the offset between 2 geometries:

Length – determines the length of specific geometry:

Angle – the angle between 2 selected elements:

Radius/Diameter – sets the radius and/or diameter of a circle/arc:

Semimajor axis – dimensions the length of the major axis of an ellipse:

Semiminor axis – dimensions the length of the minor axis of an ellipse:

Symmetry – makes sure the object is symmetrical about an axis selected. You have to select the 2 objects that will be in symmetry with one another first then select the axis of symmetry:

(Remember to hold the Ctrl key!)

Midpoint – constrains an existing point to the centre of a line:

Equidistant Point – moves an existing point to a position where it is the same point from existing geometry:

(The order in which the geometry is selected is important; first the two lines have two be selected before the point.)

Fix – prevents the selected geometry from translating:

Coincidence – moves the objects so that they are in line:

Concentricity – moves the point to the centre of the circle:

Tangency – moves lines to make them tangential to existing geometry:

Parallelism – makes two lines parallel:

Perpendicular – makes two lines perpendicular:

Horizontal – Creates a line that is horizontal:

Vertical – Creates a line that is vertical: