. Right click the 3D Circle you want (top, left or right).A 3D circles adds a circle that is correct in isometric view. You can add a top-down, left or right view of a circle. It is usually used to create symbols or add construction lines.
To add a 3d Circle:
1 Click Solid Extrusion . Right click the 3D Circle you want (top, left or right).
The prompt reads "Circle radius[prior]:"
2 Either type a radius and press ENTER or click two poinrs the correct distance apart.
The prompt reads "Center:"
3 Click a center for your circle.
4 Click to add more circles; right click to finish.