Choose Create, Arc, Arc 3 points.
Arc Three Points ribbon bar
Use this ribbon bar to create three point arcs. Click to set each of the three edge points in the graphics window.
This function allows you to enter values in the X, Y, and Z fields in AutoCursor to position any or all of the three edge points of the arc. You can also create arcs tangent to curves and points. See Guidelines for creating arcs tangent to entities for more information. Notes:
Shortcut Keys 1 – Edit point 1 (edits first point) 2 – Edit point 2 (edits second point) 3 – Edit point 3 (edits third point) T – Tangent (creates an arc tangent to one, two, or three entities) O – OK (fixes live entity and exits function) 

Guidelines for creating tangent arcs
The following are guidelines for creating arcs tangent to entities:

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