Georg Mohr
Jørgen Mohr was a Danish mathematician, known for being the first to prove the Mohr–Mascheroni theorem, which states that any geometric construction which can be done with compass and straightedge can also be done with compasses alone.
1 April 1640
Born on the same birth day (1 April): Ajit Wadekar • Annette O'Toole • Aprille Ericsson • Charles de Saint-Évremond • Clementine Churchill • David Gilliland • Ferenc Puskás • Gideon Gadot • Jofra Archer • Kevin Duckworth • Logan Paul • Nikitas Kaklamanis • Phil Niekro • Richard D. Wolff • William Harvey • Álex Palou
Born in the same month (April 1640): Gaspar Sanz