2025年中考数学二轮专题复习-专题四 辅助圆（含答案）

中小学教育资源及组卷应用平台 2025年中考二轮专题复习-几何压轴题高效拆分特训 专题四 辅助圆 INCLUDEPICTURE"标1.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标1.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标1.tif" \* MERGEFORMATINET 特训22　定点定长型INCLUDEPICTURE"标2.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 模型解读 图示 INCLUDEPICTURE"SK18-17.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-17.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\SK18-17.tif" \* MERGEFORMATINET INCLUDEPICTURE"SK18-18.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-18.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\SK18-18.tif" \* MERGEFORMATINET 条件 OA＝OB＝OC＝OD. O为定点，A为平面内一动点，且满足OA＝a. 结论 A，B，C，D四点在以点O为圆心的圆上. 点A在以点O为圆心，a为半径的圆上. INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 典题训练 1．如图，已知AB＝AC＝BC＝AD，则∠BDC＝_____． 2．如图，在四边形 ABCD 中，DC∥AB，BC＝1，AB＝AC＝AD＝2，则 BD的长为_____． 3．如图，OA⊥OB，P，Q分别是射线OA，OB上两个动点，C是线段PQ的中点，且PQ＝4，则在线段PQ滑动的过程中，点C运动形成的路径长为_____． 4．如图，在矩形ABCD中，AB＝4，AD＝8，E是AB的中点，F是BC上一点，把△BEF沿着EF翻折，点B落在点B′处，则DB′的最小值为_____． 5．如图，四边形ABCD是矩形．求证：A，B，C，D四点在同一个圆上． INCLUDEPICTURE"SK18-23.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-23.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\SK18-23.tif" \* MERGEFORMATINET INCLUDEPICTURE"标1.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标1.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标1.tif" \* MERGEFORMATINET 特训23　定弦定角型INCLUDEPICTURE"标2.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 模型解读 条件 图示及结论 在△ABC中，AB＝a(定长)，∠ACB＝α(定角)，探究点C的运动路径. INCLUDEPICTURE"SK18-24.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-24.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\SK18-24.tif" \* MERGEFORMATINET ①当α<90°时，点C的运动路径是优弧，∠AOB＝2α. INCLUDEPICTURE"SK18-25.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-25.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\De ... ...