In a right △ABC, CD (D ∈ AB) is the angle bisector of the right ∠C. Two segments, DF (F ∈ AC) and DE (E ∈BC) are drawn parallel to the legs of the triangle. Prove that DFCE is a square.
m∠CED = 180° − m∠_______= ______by reason
m∠CFD = 180° − m∠_______= ______by reason