Circles 圆|Geometry 几何学|Math 数学|Khan Academy 可汗学院共计35条视频,包括:P1 Circles glossary 圆术语汇编、P2 Radius, diameter, circumference & π 半径,直径,周长,π、P3 Proof: all circlas are similar 证明:所有的圆都是相似的等,UP主更多精彩视频,请