延长四边形ABCD的对边AD,BC交于F;DC,AB交于E,若角AED,角AFB平分线交于O,求证:角EOF=1/2(角EAF+角BCD)

问题描述:

延长四边形ABCD的对边AD,BC交于F;DC,AB交于E,若角AED,角AFB平分线交于O,求证:角EOF=1/2(角EAF+角BCD)

证明:连接OA      ∵角AED,角AFB平分线交于O      ∴ ∠EOF=∠OAB+1/2∠F+∠OAD+1/2∠E        &nbsp...