Verb conjugation of "quadrieren" in German

I hope you you had a successful week in Dortmund. Because of the bad weather at the last moment I could not get on my flight to Dusseldorf and I have stayed home. I was afraid to fly.
Take your time to answer me, do the vocabulary exercises and measure your progress! Your answers will be kept in the system itself. After that you can look at the statistics. That's pretty cool here.
You need to call before you leave... When there is good weather outside all restaurants open outside and the people sit in the sun, eat and drink. The lake is also very romantic in the late night.