BOC =90 grade=>BOC+AOC=AOD =DOB =90 grade
DOF =EOC =15 grade ; OPUSE LA FARF
BOE ==BOC-EOC =90-15 =75grade
BOF =BOD +DOF =90+15 =105 grade
AOE =AOC+EOC =90+15 =105 grade
AOB =AOC+BOC =90+90 =180 grade
PT. FIGURA DESENEAZA AB PERPENDICULAR PE CD E INTRE B SI C