Pietro Cataldi, Italian mathematician and astronomer (born 1548)

Pietro Antonio Cataldi was an Italian mathematician. A citizen of Bologna, he taught mathematics and astronomy and also worked on military problems. His work included the development of simple continued fractions and a method for their representation. He was one of many mathematicians who attempted to prove Euclid's fifth postulate.

February 11 is the 42nd day of the year in the Gregorian calendar; 323 days remain until the end of the year.