#include<bits/stdc++.h>
#define pb push_back
using namespace std;
typedef long long ll;

const int maxl=3e5+10;

int cas,k,cnt,tot;
ll n,m,ans;
int a[maxl],b[maxl];
char s[maxl];
bool in[maxl]; 

inline void prework()
{
    scanf("%lld%lld",&n,&m);
} 

inline void mainwork()
{
    if(m>n/2)
        ans=n*(n-1)/2;
    else
    {
        ans=((n-1)+(n-m))*m/2;
        ans+=(n-2*m)*m;
        ans+=m*(m-1)/2;
    }
}

inline void print()
{
    printf("%lld\n",ans);
}

int main()
{
    int t=1;
    scanf("%d",&t);
    for(cas=1;cas<=t;cas++)
    {
        prework();
        mainwork();
        print();
    }
    return 0;
}