拉手模型
https://www.bilibili.com/video/BV1mE411t7Gi/?spm_id_from=333.880.my_history.page.click
https://www.bilibili.com/video/BV1FF411j7rM/?spm_id_from=333.880.my_history.page.click
https://www.bilibili.com/video/BV1th411a7QU/?spm_id_from=333.880.my_history.page.click
https://space.bilibili.com/484303779/
https://www.bilibili.com/video/BV1cU4y1G7xr/?spm_id_from=333.788.recommend_more_video.5&vd_source=3aef498e4c7e5514308ccf833701e7af
相似三角形
https://www.zhihu.com/collection/689732911
https://zhuanlan.zhihu.com/p/719008567
https://zhuanlan.zhihu.com/p/656764356
https://zhuanlan.zhihu.com/p/581702158
全等
https://zhuanlan.zhihu.com/p/669404342
(https://zhuanlan.zhihu.com/p/493525904)
模型
https://zhuanlan.zhihu.com/p/419149184
https://zhuanlan.zhihu.com/p/717503379
面积
https://zhuanlan.zhihu.com/p/378369630
“隐圆”三兄弟
https://www.bilibili.com/video/BV1ga4y1x7Vp
【中考数学总复习】——四边形基础&手拉手、半角、倍长中线模型
https://www.bilibili.com/video/BV1Mz4y1U7JK