#include<iostream>
using namespace std;
int main()
{
    int t;
    cin>>t;
    while (t--)
    {
        int n,m,k;
        cin>>n>>m>>k;
        if((m-1)*1+(n-1)*m==k)cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
        
    }
    
}