Given: Quadrilateral DEFG is inscribed in circle P.
Prove: m∠D+m∠F=180∘
It is given that quadrilateral DEFG is inscribed in circle P. Because a circle measures 360°, mEFG + mGDE =360∘. By the Response area, 12mEF + 12mGDE =180∘. By the inscribed angles theorem, Response area = 12mGDE and Response area = 12mEFG This means m∠D+m∠F=180∘ by the
