When did Blaise Pascal create Pascal's triangle?

Answer 1

The triangular array of binomial coefficients (triangle) was discussed by Persian Mathematician Al-Karaji (953-1029) and later invented and implemented by Persian Mathematician/Astronomer/Poet Omar Khayyam in the year 1070. In the 13th century, about 200 years after Khayyam's discovery, Yang Hui (1238-1298) of China "discovered it." Now almost 400 years after Omar Khayyam's discovery, a French Mathematician Blaise Pascal (1623-1662) again "supposedly discovers" this binomial triangular array, in the 17th century.

So why is this triangle not called Khayyam's Triangle?

I'm not sure either, even with significant evidence from Khayyam's Algebra Book.

However there is your answer to when Mr. Pascal "created" it.