To Create an Arc Tangent to Three Entities
1. Click Sketch and then click the arrow next to Arc.
2. Click
3 Tangent.
3. Select an arc, circle, or line to define the first entity of tangency.
4. Select another arc, circle, or line to define the second tangent entity. The arc is previewed.
5. Select a third arc, circle, or line to define the third tangency point. The arc is created.