| 摘要 |
The invention concerns a building panel which comprises a main web of a form (when projected onto a plane surface) which is quadrilateral, preferably a parallelogram in shape, with a diagonal forming a ridge dividing the web into two triangular surfaces. Walls of triangular shape extend outwardly at an inclined angle away from the edges of the main web, the furtherest away points of the walls from the main web being along a plane through the ridge. |
