2. Second step
In the previous figure, parallel lines to EF, FD and DE have been drawn through the vertices D, E and F, respectively. By consequence, we have đ?‘Žđ?‘Ž(2 − đ?‘žđ?‘ž) đ?‘?đ?‘? đ??śđ??śđ??śđ??ś 3 3 = = 2đ?‘Žđ?‘Ž đ?‘?đ?‘?(đ?‘&#x;đ?‘&#x; + 1) đ??śđ??śđ??śđ??ś 3 3 đ?‘Žđ?‘Ž đ?‘?đ?‘?(2 − đ?‘&#x;đ?‘&#x;) đ??śđ??śđ??śđ??ś 3 3 = = 2đ?‘?đ?‘? đ?‘Žđ?‘Ž(đ?‘?đ?‘? + 1) đ??śđ??śđ??śđ??ś 3 3 đ?‘Žđ?‘Ž đ?‘?đ?‘?(2 − đ?‘?đ?‘?) đ??śđ??śđ??śđ??ś 3 3 = = 2đ?‘?đ?‘? đ?‘Žđ?‘Ž(đ?‘žđ?‘ž + 1) đ??śđ??śđ??śđ??ś 3 3 86