中考数学复习-第5单元-三角形-第23课时-相似三角形教案VIP免费

ideological and theoretical qualities and practical working ability, and strive to build a contingent of league cadres with positive work style and high quality. Hold a regular meting of the party secretary every fortnightly, arrange the work of the regiment, fedback the student information. Focus on training junior high school, junior high school secretary of the regiment branch to enable them to raise A firm political conviction, diligent and diligent learning spirit and practical and innovative work style.第五单元 三角形第 23 课时 相似三角形教学目标【考试目标】1.了解比例的基本性质，了解线段的比、成比例 线段与黄金分割；2.了解相似的意义；理解相似图形的性质，了解相似三角形判定定理和性质定理；3.了解图形的位似，能够利用位似将一个图形放大或缩小；4.利用图形的相似解决一些实际问题（如利用相似测量 旗杆的高度）.【教学重点】1.了解比例线段，掌握比例的性质.2.了解相似图形，掌握三角形相似的判定条件.3.掌握相似三角形的性质，了解位似图形.教学过程一、体系图引入，引发思考二、引入真题、归纳考点【例 1】（2024 年河北）如图，△ABC 中，∠A=78°，AB=4，AC=6.将△ABC 沿图示中的虚线剪开，剪下的阴影三角形与原三角形不相似 的是（ C ）【解析】A、阴影部分的三角形与原三角形有两个角相等，故两三角形相似，故 本选项错误；B、阴影部分的三角形与原三角形有两个角相等，故两三角形相似， 故本选项错误；Strengthen the team connection, strengthen the knowledge education among the students (especially the first grade students), and promote the formation of good school spirit with the influence of the league members. All League branches should start with recommending outstanding students as the development objects of the League, take amateur league schools as the basis, conscientiously do a good job in the work of pre-league education, league membership education, League members' vanguard exemplary consciousness education, excellent league members...