#include "bits/stdc++.h"
using namespace std;
using namespace chrono;

#define rep(i,st,en) for(__typeof(en) i=(st)-(st>en); i!=(en)-(st>en); i+=1-2*(st>en))
#define ff first
#define ss second
#define endl '\n'
#define all(v) v.begin(), v.end()
#define allr(v) v.rbegin(), v.rend()
#define finally_coding_kar_rha_hu ios_base::sync_with_stdio(0);  cin.tie(NULL);  cout.tie(NULL);
#define cases() int no_of_tc; cin>>no_of_tc; for(int testcase=1;testcase<=no_of_tc;++testcase)
typedef long long ll;
const ll mod = 1e9+7;

void _main() {
	ll x, y, k;	cin >> x >> y >> k;
	ll ans = (y-1) + ((x-1)*y);
	cout << (ans == k ? "yes" : "no") << endl;
}

int main() {
	finally_coding_kar_rha_hu
	auto timest = high_resolution_clock::now();
	cases()
	{
		// cout << "Case #" << testcase << ": ";
		_main();
	}
	auto timeen = high_resolution_clock::now();
	auto spent = duration_cast<milliseconds>(timeen - timest);
	cerr << "[Executed in " << spent.count()/1000.0 << "s]" << endl;
	return 0;
}