P5717代码：

#include<bits/stdc++.h>
using namespace std;
int a,b,c;
int main(){
cin>>a>>b>>c;
if(a*a+b*b>c*c||a*a+c*c>b*b||b*b+c*c>a*a) cout<<"Acute triangle"<<'\n';
if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a) cout<<"Right triangle"<<'\n';
if(a*a+b*b<c*c||a*a+c*c<b*b||b*b+c*c<a*a) cout<<"Obtuse triangle"<<'\n';
if(a==b||a==c||b==c) cout<<"Isosceles triangle"<<'\n';
if(a==b==c) cout<<"Equilateral triangle"<<'\n';
else cout<<"Not triangle"<<'\n';
return 0;
}