The present invention relates to a formwork plate comprising a flat rectangular central body extended in a first direction by a first series of flat tabs and in a second opposing direction by a second series of flat tabs, the tabs extending in the plane of the body while leaving a spacing between tabs of the same series, the plate having first and second sets of angled tabs, with each angled tab extending into the spacing between two flat tabs respectively from the first or second series, the tabs being angled while extending the body each having an angled portion and a flat distal end portion extending parallel to the flat tabs. The invention also relates to a formwork made from several plates.