初三圆-垂径定理(在线等)
设半径rr^2=AC^2+OC^2=(AB/2)^2+(r-CD)^2=3.6^2+(r-2.4)^2r=3.9r^2-(3/2)^2=3.9^2-1.5^2=12.96=3.6^2OC+2=(r-CD)+2=3.9-2.4+2=3.5
设半径rr^2=AC^2+OC^2=(AB/2)^2+(r-CD)^2=3.6^2+(r-2.4)^2r=3.9r^2-(3/2)^2=3.9^2-1.5^2=12.96=3.6^2OC+2=(r-CD)+2=3.9-2.4+2=3.5