To facilitate joining of base boards with high accuracy and to ensure connection between block plates with each other through a joint.
A construction block has combinations of: block plates 1 which are squares and regular triangles in planar shapes; and joints 2 which each connect the block plates 1 to each other. Of the two superimposed baseboards 3, 4 of the each block plate 1, there are formed in one baseboard 3 cut-standing pieces 5 that extend from the corners to the center by notching correspondingly to each side, while there are formed in the other baseboard 4 slits 8 that extend from the corners to the center correspondingly to the cut-standing pieces 5. With the cut standing pieces 5 raised and inserted into the slits 8, the engaging part 7 of the cut standing pieces 5 engages with the end edge of the slits 8, so hat the baseboards 3, 4 are fixed. With the inserting piece 10 of the joint 2 inserted into the receptacle 13 of the block plates 1, the constricted part 11 of the inserting piece 10 engages with the cut-standing piece 5, so that the connected state of the block plates 1 is maintained.
KICHIJO KAKA
Higashio Masahiro
Takayoshi Tagawa
Masaji Okamoto