Impossible shape.

Impossible shape.

Intertwined kitchen utensils.

Inverted faces.

It can't be difficult to draw a face.

Line D1 is perfectly straight.

Notice the handle of a cup.

Perfect cube.

Reflection of the mountain is impressive.

Shapes in figure a seem to be curved.

Spiral

Square is perfect; the sides are not bent.

The act of columns.

The blue and the green lines are the same lenght.

The building is straight.

The lines are not curved.

The lines are parallel to each other.

The lines in between are very straight.

The vertical red bars are parallel.

There is not exit.