In a right triangle abc, cd is the angle bisector of the right angle c. two lines df and de are parallel to the legs of the triangle. prove that dfce is a square. find the followingm∠ced = 180° − m∠ =   by  reason m∠cfd = 180° − m∠ =   by  reason

Please bear with my lengthy answer.

ED || CF - given
∠EDC = ∠DCF - alternate interior angles
m∠CED = 180 - (45+45) = 180 - 90 = 90° - sum of angles in a triangle is 180
∠FDC = ∠ECD - alternate interior angles
m∠CFD = 180 - (45+45) = 180 - 90 = 90° - sum of angles in a triangle is 180
m∠EDF = 360 - (90+90+90) = 360 - 270 = 90° - sum of angles in a quadrilateral is 360