如图∠CDA=∠CBA DE平分∠CDA BF平分∠CBA 且∠ADE=∠AED求证DE//FB??
2011-03-16 11:54:24 作者:我乐NBA 来源:NBA中文网 浏览次数:0
如图∠CDA=∠CBA DE平分∠CDA BF平分∠CBA 且∠ADE=∠AED求证DE//FB??
∠ADE=∠CDE=∠AED,又∠CDE=∠ABF,故∠AED=∠ABF,所以DE//FB
∠ADE=∠CDE=∠AED,又∠CDE=∠ABF,故∠AED=∠ABF,所以DE//FB