#include<bits/stdc++.h>
 
using namespace std;
 
int main()
{
  int t;
  scanf("%d",&t);
  while(t--)
  {
    long long a,b,c;
    scanf("%lld%lld%lld",&a,&b,&c);
    printf((a*b) -1 == c? "YES\n" :"NO\n");
  }

  return 0;
}