Tangent snap

Use the Tangent snap to snap to the tangent point of another entity. You can snap to the point on an arc, ellipse, spline, or circle that, when connected to the previous point, forms a line tangent to that entity.

To set the Tangent snap       

Do one of the following to choose Tangent ():

    On the ribbon, choose Draw > Tangent (in Entity Snaps).

    On the menu, choose Tools > Entity Snaps > Tangent.

    On the Entity Snaps toolbar, click the Tangent tool.

    Type tangent and then press Enter.