#include<iostream>
using namespace std;
void solve(){
    long long n,m,k;
    cin>>n>>m>>k;
    long long s=n*m-1;
    if(s==k)
    {
        cout<<"yes"<<endl;
    }
    else{
    cout<<"No"<<endl;
    }
}

int main(){
   int t;
   cin>>t;
   while(t--)
   {
   solve();
   }
}