问题
填空题
已知⊙O1与⊙O2内切,O1O2=6cm,⊙O1的半径为8cm,则⊙O2的半径为______.
答案
设两圆半径为r1、r2,两圆内切,
当r1>r2时,r1-r2=O1O2,即8-r2=6,解得r2=2;
当r1<r2时,r2-r1=O1O2,即r2-8=6,解得r2=14.
故⊙O2的半径为2cm或14cm.
已知⊙O1与⊙O2内切,O1O2=6cm,⊙O1的半径为8cm,则⊙O2的半径为______.
设两圆半径为r1、r2,两圆内切,
当r1>r2时,r1-r2=O1O2,即8-r2=6,解得r2=2;
当r1<r2时,r2-r1=O1O2,即r2-8=6,解得r2=14.
故⊙O2的半径为2cm或14cm.