Tangent Arc Tool
Use the Sheet Metal Tangent Arc tool to sketch an arc that is tangent to a curve or line in your design.
Lines, splines, and arcs are extruded to the thickness of a sheet metal wall when they form a closed profile. You can change the default wall thickness in the sheet metal properties.
In addition, you can choose the Profile option to create a wall that is perpendicular to the sketch plane as you sketch.