. Circular rooms are always drawn with facing walls showing.Adds a circular room with a floor and wall to the drawing. The appearance of the surfaces is determined by the current Perspectives Settings . Circular rooms are always drawn with facing walls showing.
To add a circular room:
1 On the Perspectives toolbar right-click Rectangular Room 
then click Polygonal Room.
The prompt reads "Wall width[n]"
2 Either type a thickness and press ENTER or click two points the required distance apart, or right click to accept the default (previous) value.
The prompt reads "Center"
2 Click a center for your circular floor.
The prompt reads "point on circle or enter radius[previous] (TAB switch inside/outside):"
3 Click a point on the circumfrence of your circle, type a radius and press ENTER, or right click to accept the default (previous radius). The TAB key on this prompt switches the final click between the inside and outside of the wall
The prompt reads "Height[n]:"
6 Either click a point on the top of the wall, or type a height then press ENTER or right click to accept the default (previous) value.