9月MATHJJ的不解之处,请NN回复

inlovesummer

以下是引用whatapain在2006-9-24 0:37:00的发言：

说有个三角形，边A、B、C。
   问是否是right angle。
    E
1）A^2+B^2=3^2+4^2
2)  A^2+C^2=3^2+5^2

this problem is testing ur carefulness, as we know, 3,4,5 can constitute a right triangle.

but what the question says is a^2 +b^2=3^2 +4^2 (which is 25), lots of numbers of a and b can meet this standard (a^2+b^2=25), the question does not tell you that one equals to 3, and the other is 4.

be careful

请问如果写明是A.BC三边是整数应当可以选A吧