如图,在四边形ABCD中,E是AD上一点,延长CE到点F,使.
(1) 求证:
(2) 用直尺和圆规在AD上作出一点P,使△BPC∽△CDP(保留作图痕迹,不写作法)。
如图,在四边形ABCD中,E是AD上一点,延长CE到点F,使.
(1) 求证:
(2) 用直尺和圆规在AD上作出一点P,使△BPC∽△CDP(保留作图痕迹,不写作法)。
解析:(1)证明:∵ 四边形ABCD 是平行四边形,
∴ AD∥BC.
∴ ∠CED=∠BCF.
∵ ∠CED+∠DCE+∠D=180°,∠BCF+∠FBC+∠F=180°,
∴ ∠D=180°-∠CED-∠DCE,∠F=180°-∠BCF-∠FBC.
又∠DCE=∠FBC,
∴ ∠D=∠F. ······························································· 4 分
(2)图中P 就是所求作的点. ··································································· 7 分