a

for (int i = 0; i < a; i++)
  for (int j = 0; j < a; j++)
    for (int k = 0; k < a; k++)
       {
        abs(t1 = sqrt( pow(X[j] - X[i],2) + pow(Y[j] - Y[i],2)));
        abs(t2 = sqrt( pow(X[k] - X[j],2) + pow(Y[k] - Y[j],2)));
        abs(t3 = sqrt( pow(X[i] - X[k],2) + pow(Y[i] - Y[k],2)));
        if ( (t1*t1 + t2*t2 == t3*t3) && (t3 != 0 )  ) {
          D[l] = t1 * t2 / 2;
          l++;
          Memo1->Lines->Add((D[l]));
          }
        if ( (t1*t1 + t3*t3 == t2*t2) && (t2 != 0 ) ) {
          D[l] = t1 * t3 / 2;
          l++;
          Memo1->Lines->Add((D[l]));
          }
          if ( (t2*t2 + t3*t3 == t1*t1) && (t1 != 0 )  )  {
          D[l] = t2 * t3 / 2;
          l++;
          Memo1->Lines->Add((D[l]));
          }


     }
}