Causes selected lines to lie 90 degrees to one another.

Button
Ribbon: Parametric tab
Geometric
panel
PerpendicularNot available on the ribbon
in the current workspace
Menu: Parametric
Geometric
Constraints
PerpendicularNot available in menus
in the current workspace
Toolbar: Geometric
Constraint
This command is equivalent to the Perpendicular option in GEOMCONSTRAINT.
Lines do not have to intersect to be perpendicular.
Following are the valid constraint objects and points: