file:加鸡娃群实时更新资料，不怕保存不上~.png file:几何变换之平移.pdf file:(2)几何变换之平移例3-例5.mp4 file:中位线与斜边中线.pdf file:(4)中位线与斜边中线例5-例6.mp4 file:正方形和梯形（下）.pdf file:(4)正方形和梯形（下）例3-例4.mp4 file:(5)平行四边形，菱形及矩形（下）例5.mp4