#include<iostream>
#include<algorithm>
#include<queue>
#include<utility>
#include<cmath>
#pragma warning(disable:4996)
#define inf 0x3f3f3f3f
typedef long long ll;
using namespace std;
int main()
{
    int t;
    cin >> t;
    while (t--) {
        int n;
        ll a, b;
        scanf("%lld%lld", &a, &b);
        if (b >= a / 2) {
            cout << a * (a - 1) / 2 << endl;
        }
        else {
            ll sum = 0;
            sum += (2 * a - b - 1) * b / 2;
            sum += (a - 2 * b) * b;
            sum += (b - 1) * b / 2;
            cout << sum << endl;
        }
    }
    return 0;
}