designed so that only a single type of panel is needed fig5 a shows a view of forming panel 25 a from underneath so that its structure is visible in particular side flanges 51 a and 51 b are shown extending along either side of forming panel 25 a and end flanges 54 a and 54 b are shown at either end of forming panel 25 a in addition ribs 53 a 53 e are shown extending across panel 25 a from one side to the other to provide stiffness and structural strength to panel 25 a the dimensions of forming panel 25 a are approximately six feet 6 u2032 by three feet 3 u2032 with two cut off corners measuring four inches 4 u2033 in one example forming panel 25 a is made fractionally less than these dimensions for example less by 1 32 of an inch in each dimension this gives dimensions of five feet eleven and thirty one thirty seconds inches 5 u2032 11 31 32 u2033 by two feet eleven and thirty one thirty seconds inches 2 u2032 11 31 32 u2033 the dimensions of panel 25 a are such that it has sufficient strength to support concrete while being light enough to be easily handled fig5 b shows a view of forming panel 27.