When curving an element such as a wall or floor opening, you can use the Commander to specify a precise curve angle.
Radius. The distance from the element (in its uncurved state) to the center point of the curve.
Included Angle. The angle formed between two radius lines extending from the center of the circle implied by the curve out to the endpoints of the arc. The larger the angle, the rounder and larger the curve.
It is not necessary to enter both the Radius and Included Angle values. If you enter one, the program automatically supplies the other. Also, if you enter a value and nothing happens after you press ENTER, then the value is not valid in relation to the dimensions of your element.