如图所示,小圆半径为15,则大圆半径为()
A.47.883B.48.742C.48.541D.48.151
单项选择题如图所示,多段线的总长度是多少()
A.130.527B.192.306C.179.171D.179.205
单项选择题如图所示,矩形长度为23,面积为211,则其内切椭圆的周长是多少()
A.64.348B.52.9C.28.821D.165.719