user interface It is possible to make a combination of the following objects: Point, line, plane, circle, sphere, line between 2 points, triangle, quadliteral
The output is a text and for 2 dimensions a describing picture.
Before calculation there is a check, whether the user input is valid for this geometrical objekt. If not you get a hint and the object is converted to the closest object. (e.g. a sphere with radius 0 becomes a point)