Though the Pythagorean theorem is attributed to Pythagoras, a mathematician and philosopher who lived in the 6th century BC, the first proof had not been completed before the year 300 BC, when it appeared in Euclid’s Elements.
A. the first proof had not been completed before the year
B. it had not been proven to be true before the year
C. the first proof of the theorem was not completed prior to
D. the first proof was not completed until
E. it was not proven to be true prior to
Source: 800 Test
A. the first proof had not been completed before the year
B. it had not been proven to be true before the year
C. the first proof of the theorem was not completed prior to
D. the first proof was not completed until
E. it was not proven to be true prior to
Source: 800 Test