A:线粒体和细胞质基质
B:线粒体基质
C:肺泡
D:细胞质基质
I'm hungry.
若一段圆弧的长度等于该圆内接正三角形的边长,则这段弧所对圆心角弧度为( )
Shu-How Lin is now one of__________ basketball players in the NBA.
(Ⅰ)求B,C点的坐标;
(Ⅱ)求△ABC的外接圆方程.