#include <bits/stdc++.h>
using namespace std;
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n,m,k,cnt=0;
        cin>>n>>m>>k;
        cnt+=(n-1)+(m-1)*n;
        if(cnt==k) cout<<"yes"<<endl;
        else cout<<"no"<<endl;
    }
}
