short side 5 a and two long sides 4 a 4 b of a floorboard 1 u2032 of the same type c and also to a short side 5 a and one long side 4 b of the first a and the second type b of floorboards moreover the floorboard c has one short side 5 a and two long sides 4 b which can be locked to a neighboring short side 5 b of a floorboard 1 u2032 of the same type c and also to a long side 4 a and to a short side 5 b of the first a and the second type b joining of the above mentioned three essentially identical sides 4 b and 5 a of the third type c to the long sides 4 a of the two mirror inverted boards of the first a and the second type b can take place by an angular motion and this joining can take place both in the vertical and in the horizontal direction joining of a and b panels to each other could be made in the following way the long sides 4 a could be locked to adjacent long sides 4 b vertically and horizontally with angling joining.