Quadrilateral CDEF is inscribed in circle A. Which statements complete the proof to show that ∠CFE and ∠CDE are supplementary?

Quadrilateral CDEF is inscribed in circle A, so mARC CDE + mARC CFE= 360°. ∠CFE and ∠CDE are inscribed angles, which means that their measures are _. So, _. Using the substitution property of equality, 2 ⋅ m∠CFE + 2 ⋅ m∠CDE = 360°. Using the division property of equality, divide both sides of the equation by 2, resulting in m∠CFE + m∠CDE = 180°. Therefore, ∠CFE and ∠CDE are supplementary.