∵ Two circles intersect at point A and point B, the length of AB is 6cm, the radius of big circle is 5cm, and the radius of small circle is 13 cm.

∴AB⊥O 1 O 2，

∴o 1 O2 = 5 ^ 2-3 ^ 2+( 13)2-3 ^ 2 = 6(cm)，

As shown in Figure 2:

∵ Two circles intersect at point A and point B, the length of AB is 6cm, the radius of big circle is 5cm, and the radius of small circle is 13 cm.

∴AB⊥O 1 O 2，

∴o 1 O2 = 5 2-3 2-( 13)2-3 2 = 2(cm)，

So what Wang Ping and Li Wei said is not comprehensive, and the answer is 6cm or 2 cm.

Through this question, we can get the rigor of mathematical thinking and pay attention to classified discussion.