# Perpendicular to Curve

[Perpendicular to Curve] command defines CPlane that is vertical to a select a curve.

For a point on the selected curve, the pricipal normal will be X axis of the updated CPlane. Y axis is perpendicular to X axis and the tangent at the point(binormal).

## Step 1

While "Specify Curve" prompt is displayed, select a curve.

After the curve selection is done, the preview of new CPlane will be shown.

## Step 2

While "Specify a point on the curve" is displayed, locate a point on the curve by Mouse. "Snap On Curve" mode will be active automatically.

The updated Y axis will be dynamically shown according to the mouse cursor movement in the screen preview.