When we constrain, we fix geometry and relate its orientation and position to other geometry in a particular work plane. This ensures appropriate behavior when geometry resizes. Certain constraints are automatically applied.

- When creating line or arc geometry using the Content Builder, points are placed at endpoints along with coincident constraints which keep the point and end of line always in the same location.
- When creating rectangular profiles, coincident constraints are placed where the endpoints and points coincide and perpendicular constraints are placed on the lines forming corners.
- When oval profiles are created, parallel constraints are placed between the two parallel lines, tangent constraints are placed where the arcs and lines intersect and coincident constraints are placed on endpoints and points.

We can also apply constraints manually when we create custom profiles. The following constraints are available:

Tangent - Maintains tangency between two arcs, or an arc and a line.

Parallel - Forces two lines to remain parallel.

Perpendicular - Forces two lines to remain perpendicular

Concentric - Maintains location of a point at the center of an arc or circle. Will also force arcs and circles to maintain the same center point.

Coincident - Forces two types of geometry to occupy the same position.

Equal Distance - Maintains an equal distance between three points.

Equal Radius - Maintains an equal radius between arcs and circles.

Midpoint - Forces the position of a point to be equidistant between two lines.

Symmetric - Maintains symmetry about a line.

Normal - Forces a curve to intersect a line or curve where its tangent is perpendicular.

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