Kawasaki's theorem
... that according to Kawasaki's theorem, an origami crease pattern with one vertex may be folded flat if and only if the sum of every other angle between consecutive creases is 180º?
... that according to <b id="mwBrc"><a href="./Kawasaki's_theorem" id="mwBrg" rel="mw:WikiLink" title="Kawasaki's theorem">Kawasaki's theorem</a></b>, an <a href="./Origami" id="mwBrk" rel="mw:WikiLink" title="Origami">origami</a> <a href="./Crease_pattern" id="mwBro" rel="mw:WikiLink" title="Crease pattern">crease pattern</a> with one <a href="./Vertex_(geometry)" id="mwBrs" rel="mw:WikiLink" title="Vertex (geometry)">vertex</a> may be <a class="mw-redirect" href="./Flat-foldability" id="mwBrw" rel="mw:WikiLink" title="Flat-foldability">folded flat</a> <i id="mwBr0">(pictured)</i> if and only if the sum of every other angle between consecutive creases is 180º?