What constraint ensures that two selected lines meet at a right angle?

The constraint that ensures two selected lines meet at a right angle is the Perpendicular constraint. When applied in a design software such as Autodesk Inventor, this constraint geometrically fixes the angle between the two lines to precisely 90 degrees. This is essential in many engineering and architectural applications where right angles are necessary for structural integrity and functionality.

By adding the Perpendicular constraint, the software automatically adjusts the lines if they are moved or modified, maintaining that right angle relationship. This is critical in sketching and modeling, as it helps ensure that components fit together correctly and perform as designed.

The other constraints serve different purposes: the Parallel constraint maintains a consistent distance and angle between two lines without forcing them to meet at a right angle. The Collinear constraint keeps two lines on the same straight path, which might not mean they intersect perpendicularly. Lastly, the Tangent constraint relates to curves and straight lines, maintaining a single touching point rather than defining an angle between two straight lines. Understanding these distinctions helps in effective sketching and assembly within the software.