Tangent Snap tool

Use the Tangent Snap tool 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 Snap ():

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

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

    On the Entity Snaps toolbar, click the Set Tangent Snap tool.

    Type tangent and then press Enter.