Abstract: An interlocking construction arrangement for coupling together two members at a predetermined angular relationship. A male joining means is coupled to the first member and has an outwardly upstanding male portion extending from the first member at the predetermined angular relationship. A female joining means is coupled to the second member and the female joining means has walls defining a male portion receiving cavity. When it is desired to join the two members together the male portion is inserted into the cavity of the female joining means where it may be frictionally retained to provide a removable coupling between the members or bonded or otherwise secured together to provide a permanent coupling of the two members.